diff --git a/src/blenderbim/blenderbim/bim/module/drawing/decoration.py b/src/blenderbim/blenderbim/bim/module/drawing/decoration.py
index a1eb06b3a8..877d689dba 100644
--- a/src/blenderbim/blenderbim/bim/module/drawing/decoration.py
+++ b/src/blenderbim/blenderbim/bim/module/drawing/decoration.py
@@ -32,6 +32,12 @@ from mathutils import Vector, Matrix
 from bpy_extras.view3d_utils import location_3d_to_region_2d
 from gpu.types import GPUShader, GPUBatch, GPUIndexBuf, GPUVertBuf, GPUVertFormat
 from gpu_extras.batch import batch_for_shader
+from math import acos, pi
+
+
+def ccw(A, B, C):
+    """whether a-b-c located in counter-clockwise order in 2d space"""
+    return (C.y - A.y) * (B.x - A.x) > (B.y - A.y) * (C.x - A.x)
 
 
 class BaseDecorator:
@@ -66,6 +72,42 @@ class BaseDecorator:
         }
     }
 
+    bool check_counterclockwise(in vec4 A, in vec4 B, in vec4 C) {
+        return (C.y-A.y) * (B.x-A.x) > (B.y-A.y) * (C.x-A.x);
+    }
+
+    void angle_circle_head(
+        in vec4 circle_start, in float circle_angle,
+        in bool counterclockwise,
+        out vec4 head[CIRCLE_SEGS+1], out float angle_segs) {
+        
+        // 1 added to CIRCLE_SEGS because we're number of vertices
+        // for n segments is n+1
+        
+        float angle_d;
+        angle_d = PI * 2 / CIRCLE_SEGS; // 30d
+        // need to bottom clamp it to 1, otherwise it causes Blender crash at extruding the curve
+        angle_segs = max(1, ceil(circle_angle / angle_d));
+        angle_d = circle_angle / angle_segs;
+        
+        for(int i = 0; i < (angle_segs + 1); i++) {
+            float angle = angle_d * i;
+            if (counterclockwise) {
+                head[i] = vec4(
+                    circle_start.x *  cos(-angle) + circle_start.y * sin(-angle),
+                    circle_start.x * -sin(-angle) + circle_start.y * cos(-angle),
+                    0, 0
+                );
+            } else {
+                 head[i] = vec4(
+                    circle_start.x *  cos(angle) + circle_start.y * sin(angle),
+                    circle_start.x * -sin(angle) + circle_start.y * cos(angle),
+                    0, 0
+                );
+            }
+        }
+    }
+
     void cross_head(in vec4 dir, in float size, out vec4 head[3]) {
         vec4 nose = dir * size;
         float c = cos(PI/2), s = sin(PI/2);
@@ -79,12 +121,15 @@ class BaseDecorator:
     uniform mat4 viewMatrix;
     in vec3 pos;
     in uint topo;
+    in vec3 next_vert;
     out vec4 gl_Position;
     out uint type;
+    out vec4 v_next_vert;
 
     void main() {
         gl_Position = viewMatrix * vec4(pos, 1.0);
         type = topo;
+        v_next_vert = viewMatrix * vec4(next_vert, 1.0);
     }
     """
 
@@ -267,7 +312,13 @@ class BaseDecorator:
         """perform actual drawing stuff"""
         raise NotImplementedError()
 
-    def draw_lines(self, context, obj, vertices, indices, topology=None, is_scale_dependant=True):
+    def draw_lines(
+        self, context, obj, vertices, indices, topology=None, is_scale_dependant=True, fill_next_vertices=False
+    ):
+        # use is_scale_dependant = False if shader is not using uniform viewportDrawingScale
+        # otherwise uniform will be discarded during the optimization process
+        # and you will get "ValueError: GPUShader.uniform_float: uniform viewportDrawingScale not found"
+
         region = context.region
         region3d = context.region_data
         color = context.scene.DocProperties.decorations_colour
@@ -276,12 +327,18 @@ class BaseDecorator:
         fmt.attr_add(id="pos", comp_type="F32", len=3, fetch_mode="FLOAT")
         if topology:
             fmt.attr_add(id="topo", comp_type="U8", len=1, fetch_mode="INT")
+        if fill_next_vertices:
+            fmt.attr_add(id="next_vert", comp_type="F32", len=3, fetch_mode="FLOAT")
 
         vbo = GPUVertBuf(len=len(vertices), format=fmt)
         vbo.attr_fill(id="pos", data=vertices)
         if topology:
             vbo.attr_fill(id="topo", data=topology)
 
+        if fill_next_vertices:
+            shifted_vertices = vertices[1:] + [vertices[0]]
+            vbo.attr_fill(id="next_vert", data=shifted_vertices)
+
         ibo = GPUIndexBuf(type="LINES", seq=indices)
 
         batch = GPUBatch(type="LINES", buf=vbo, elem=ibo)
@@ -480,6 +537,132 @@ class DimensionDecorator(BaseDecorator):
             self.draw_label(context, text, p0 + (dir) * 0.5, dir)
 
 
+class AngleDecorator(BaseDecorator):
+    """Decorator for angle objects
+    - each edge of a segment with arrow
+    - every non-last edge has angle circle
+    - every circle is labeled with angle in degrees
+    """
+
+    objecttype = "ANGLE"
+
+    DEF_GLSL = (
+        BaseDecorator.DEF_GLSL
+        + """
+        #define ARROW_ANGLE PI / 12.0
+        #define ARROW_SIZE 8.0
+        #define CIRCLE_SIZE 6.0
+    """
+    )
+
+    GEOM_GLSL = """
+    uniform vec2 winsize;
+    uniform float viewportDrawingScale;
+
+    layout(lines) in;
+    layout(line_strip, max_vertices=MAX_POINTS) out;
+    in uint type[];
+    in vec4 v_next_vert[];
+    
+    // per edge shader
+    void main() {
+        vec4 clip2win = matCLIP2WIN();
+        vec4 win2clip = matWIN2CLIP();
+
+        vec4 p0 = gl_in[0].gl_Position, p1 = gl_in[1].gl_Position;
+        vec4 p2 = v_next_vert[1];
+        uint t0 = type[0], t1 = type[1];
+
+        vec4 p0w = CLIP2WIN(p0), p1w = CLIP2WIN(p1);
+        vec4 p2w = CLIP2WIN(p2);
+        vec4 edge0 = p1w - p0w, dir = normalize(edge0);
+
+        vec4 p;
+        // draw a segment line
+        p = p0w;
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        p = p1w;
+        gl_Position = WIN2CLIP(p);
+        EmitVertex();
+        EndPrimitive();
+
+        // end edge with angle circle for the non-last segment
+        if (t1 == 0u) { // draws only on internal vertex
+            edge0 = p0w - p1w;
+            vec4 dir0 = normalize(edge0);
+            vec4 edge1 = p2w - p1w;
+            vec4 dir1 = normalize(edge1);
+
+            float angle_circle_size = min( length(edge0), length(edge1) );
+            vec4 circle_start = dir0 * angle_circle_size;
+            vec4 circle_end = dir1 * angle_circle_size;
+
+            float cos_a = dot( edge0, edge1 ) / ( length(edge0) * length(edge1) );
+            float circle_angle = acos(cos_a);
+
+            vec4 circle_head_data[CIRCLE_SEGS+1];
+            float angle_segs;
+            bool counterclockwise = check_counterclockwise(p2w, p1w, p0w);
+            angle_circle_head(
+                circle_start,
+                circle_angle,
+                counterclockwise,
+                circle_head_data,
+                angle_segs);
+
+            for(int i=0; i<angle_segs+1; i++) {
+                p = p1w + circle_head_data[i];
+                gl_Position = WIN2CLIP(p);
+                EmitVertex();
+            }
+            EndPrimitive();
+        }
+    }
+    """
+
+    def decorate(self, context, obj):
+        verts, idxs, topo = self.get_path_geom(obj)
+        self.draw_lines(context, obj, verts, idxs, topo, fill_next_vertices=True, is_scale_dependant=False)
+        self.draw_labels(context, obj, verts, idxs)
+
+    def draw_labels(self, context, obj, vertices, indices):
+        region = context.region
+        region3d = context.region_data
+
+        last_segment_i = len(indices) - 1
+        for edge_i, edge_vertices in enumerate(indices):
+            if edge_i == last_segment_i:
+                continue
+
+            # draw angle label
+            i0, i1 = edge_vertices
+            v0 = Vector(vertices[i0])
+            v1 = Vector(vertices[i1])
+            v2 = Vector(vertices[i1 + 1])
+            p0 = location_3d_to_region_2d(region, region3d, v0)
+            p1 = location_3d_to_region_2d(region, region3d, v1)
+            p2 = location_3d_to_region_2d(region, region3d, v2)
+
+            edge0 = p0 - p1
+            edge1 = p2 - p1
+            cos_a = edge0.dot(edge1) / (edge0.length * edge1.length)
+            circle_angle = acos(cos_a) / pi * 180
+
+            text = f"{int(circle_angle)}d"
+
+            # TODO: set label position pased on p1
+            # + y relative to p0p1 if p0p1p2 is clockwise
+            # - y relative to p0p1 if p0p1p2 is counter-clockwise
+            # counter_clockwise = ccw(p0, p1, p2)
+            # label_position = (p1 + Vector( (0, 10) ) * (1 if counter_clockwise else -1)) + edge1 * 0.1
+            label_position = p1 + edge1 * 0.1
+
+            # TODO: set label direction based on the first edge (p0, p1)
+            label_dir = Vector((1, 0))
+            self.draw_label(context, text, label_position, label_dir)
+
+
 class DiameterDecorator(DimensionDecorator):
     objecttype = "DIAMETER"
 
@@ -895,7 +1078,6 @@ class LevelDecorator(BaseDecorator):
     def decorate(self, context, obj):
         verts, idxs, topo = self.get_path_geom(obj)
         self.draw_lines(context, obj, verts, idxs, topo)
-        splines = self.get_splines(obj)
         self.draw_labels(context, obj, splines)
 
 
@@ -1585,6 +1767,7 @@ class TextDecorator(BaseDecorator):
 class DecorationsHandler:
     decorators_classes = [
         DimensionDecorator,
+        AngleDecorator,
         GridDecorator,
         HiddenDecorator,
         LeaderDecorator,
diff --git a/src/blenderbim/blenderbim/bim/module/drawing/svgwriter.py b/src/blenderbim/blenderbim/bim/module/drawing/svgwriter.py
index eba6c3c1e8..bbcf00460f 100644
--- a/src/blenderbim/blenderbim/bim/module/drawing/svgwriter.py
+++ b/src/blenderbim/blenderbim/bim/module/drawing/svgwriter.py
@@ -34,6 +34,7 @@ import blenderbim.bim.module.drawing.annotation as annotation
 from mathutils import Vector
 from mathutils import geometry
 from blenderbim.bim.ifc import IfcStore
+from bpy_extras import view3d_utils
 
 
 class External(svgwrite.container.Group):
@@ -140,6 +141,8 @@ class SvgWriter:
                 self.draw_dimension_annotations(obj)
             elif element.ObjectType == "ANGLE":
                 self.draw_angle_annotations(obj)
+            elif element.ObjectType == "ANGLE_OLD":
+                self.draw_angle_old_annotations(obj)
             elif element.ObjectType == "RADIUS":
                 self.draw_radius_annotations(obj)
             elif element.ObjectType == "DIAMETER":
@@ -619,19 +622,52 @@ class SvgWriter:
             )
 
     def draw_angle_annotations(self, obj):
+        # calculate p3 which is the center of the arc
+        # to use draw_svg_3point_arc()
+        points = obj.data.splines[0].points
+        region = bpy.context.region
+        region_3d = bpy.context.area.spaces.active.region_3d
+        points_2d = [view3d_utils.location_3d_to_region_2d(region, region_3d, p.co.xyz) for p in points]
+
+        edge0 = points_2d[0] - points_2d[1]
+        edge1 = points_2d[2] - points_2d[1]
+        angle_radius = min(edge0.length, edge1.length)
+        dir0 = edge0.normalized()
+        dir1 = edge1.normalized()
+        dir2 = ((dir0 + dir1) / 2).normalized()
+
+        p3 = points_2d[1] + dir2 * angle_radius
+
+        # make all edges the same radius
+        p0 = points_2d[1] + dir0 * angle_radius
+        p2 = points_2d[1] + dir1 * angle_radius
+        points = [view3d_utils.region_2d_to_origin_3d(region, region_3d, p) for p in [p0, p3, p2]]
+        # points = [p.co.xyz for p in bpy.context.object.data.splines[0].points[:3]]
+
+        bm = bmesh.new()
+        bm.verts.index_update()
+        bm.edges.index_update()
+        new_verts = [bm.verts.new(p) for p in points]
+        new_edges = [bm.edges.new( (new_verts[e[0]], new_verts[e[1]]) ) for e in ((0, 1), (1, 2))]
+        self.draw_svg_3point_arc(obj, bm)
+
+    def draw_angle_old_annotations(self, obj):
+        bm = bmesh.new()
+        bm.from_mesh(obj.data)
+        bm.verts.ensure_lookup_table()
+        self.draw_svg_3point_arc(obj, bm)
+
+    def draw_svg_3point_arc(self, obj, bm):
         # This implementation uses an SVG arc, which means that it can only draw
         # arcs that are orthogonal to the view (e.g. not arcs in 3D).
         # Gosh this is bad code :(
-        x_offset = self.raw_width / 2
-        y_offset = self.raw_height / 2
+
+        points = [v.co for v in bm.verts][:3]
+        center = tool.Cad.get_center_of_arc(points, obj)
         classes = self.get_attribute_classes(obj)
         matrix_world = obj.matrix_world
-
-        points = [v.co for v in obj.data.vertices][:3]
-        center = tool.Cad.get_center_of_arc(points, obj)
-
-        bm = bmesh.new()
-        bm.from_mesh(obj.data)
+        x_offset = self.raw_width / 2
+        y_offset = self.raw_height / 2
         bm.verts.ensure_lookup_table()
         arc_end_verts = [v for v in bm.verts if len(v.link_edges) == 1]
         arc_end_pts = [matrix_world @ v.co for v in arc_end_verts]
@@ -680,11 +716,11 @@ class SvgWriter:
 
         # Center of gravity of all vertices, used to help position the text
         cog = Vector((0, 0, 0))
-        for vert in obj.data.vertices:
-            cog += vert.co
-        cog = matrix_world @ (cog / len(obj.data.vertices))
+        for point in points:
+            cog += point
+        cog = matrix_world @ (cog / len(points))
 
-        radius = ((matrix_world @ obj.data.vertices[0].co) - center).length
+        radius = ((matrix_world @ points[0]) - center).length
 
         arc_midpoint = center + ((cog - center).normalized() * radius)
 
diff --git a/src/blenderbim/blenderbim/bim/module/drawing/ui.py b/src/blenderbim/blenderbim/bim/module/drawing/ui.py
index 9692049e10..886cfec726 100644
--- a/src/blenderbim/blenderbim/bim/module/drawing/ui.py
+++ b/src/blenderbim/blenderbim/bim/module/drawing/ui.py
@@ -171,10 +171,10 @@ class BIM_PT_drawings(Panel):
                 active_drawing = self.props.drawings[self.props.active_drawing_index]
                 row = self.layout.row(align=True)
                 col = row.column()
-                col.alignment = 'LEFT'
+                col.alignment = "LEFT"
                 col.operator("bim.remove_drawing", icon="X", text="").drawing = active_drawing.ifc_definition_id
                 col = row.column()
-                col.alignment = 'RIGHT'
+                col.alignment = "RIGHT"
                 op = row.operator("bim.open_view", icon="URL", text="")
                 op.view = active_drawing.name
                 op = row.operator("bim.activate_view", icon="OUTLINER_OB_CAMERA", text="")
@@ -376,6 +376,9 @@ class BIM_PT_annotation_utilities(Panel):
         op.data_type = "curve"
         op = row.operator("bim.add_annotation", text="Angle", icon="DRIVER_ROTATIONAL_DIFFERENCE")
         op.object_type = "ANGLE"
+        op.data_type = "curve"
+        op = row.operator("bim.add_annotation", text="Angle (old)", icon="DRIVER_ROTATIONAL_DIFFERENCE")
+        op.object_type = "ANGLE_OLD"
         op.data_type = "mesh"
 
         row = layout.row(align=True)
diff --git a/src/blenderbim/blenderbim/bim/module/model/slab.py b/src/blenderbim/blenderbim/bim/module/model/slab.py
index 9e994a98b9..dbef621f29 100644
--- a/src/blenderbim/blenderbim/bim/module/model/slab.py
+++ b/src/blenderbim/blenderbim/bim/module/model/slab.py
@@ -173,7 +173,7 @@ class DumbSlabGenerator:
                 matrix_world[2][3] = self.collection_obj.location[2] - self.depth
             else:
                 matrix_world[2][3] -= self.depth
-            obj.matrix_world = Matrix.Rotation(self.x_angle, 4, 'X') @ matrix_world
+            obj.matrix_world = Matrix.Rotation(self.x_angle, 4, "X") @ matrix_world
             bpy.context.view_layer.update()
             self.collection.objects.link(obj)
 
@@ -651,6 +651,7 @@ class EditExtrusionProfile(bpy.types.Operator, tool.Ifc.Operator):
         profile = tool.Model.export_profile(obj, position=position)
 
         if not profile:
+
             def msg(self, context):
                 self.layout.label(text="INVALID PROFILE: " + indices[1])
 
@@ -784,7 +785,7 @@ class DecorationsHandler:
         special_vertex_indices = {}
         selected_edges = []
         unselected_edges = []
-        special_edges = []
+        special_edges = []  # edges that have a circle or an arc associated with them
 
         arc_groups = []
         circle_groups = []
diff --git a/src/blenderbim/blenderbim/tool/drawing.py b/src/blenderbim/blenderbim/tool/drawing.py
index 3dbab91995..a56c79256d 100644
--- a/src/blenderbim/blenderbim/tool/drawing.py
+++ b/src/blenderbim/blenderbim/tool/drawing.py
@@ -38,7 +38,8 @@ class Drawing(blenderbim.core.tool.Drawing):
     @classmethod
     def create_annotation_object(cls, drawing, object_type):
         data_type = {
-            "ANGLE": "mesh",
+            "ANGLE": "curve",
+            "ANGLE_OLD": "mesh",
             "BREAKLINE": "mesh",
             "DIAMETER": "curve",
             "DIMENSION": "curve",