Angles, triangles and circles
Recognise the model, justify the rule and solve independently.
IKMC Grades 7-8 - Selected Topics
Explain why adjacent angles on a straight line add up to 180 degrees and angles around a point add up to 360 degrees.
Use the angle sum of a triangle and the exterior-angle property, stating which triangle each step uses.
Explain why an angle bisector splits an angle into two equal angles, and say when it also bisects the opposite side.
Split a convex polygon into triangles from one vertex and explain why its interior angles add up to $(n-2)180$ degrees.