Students use the angle between a tangent and a radius property and the base angles in an isosceles triangle property to find an unknown angle and to explain why line segments are of equal size.
Students use their knowledge of the interior angles of regular polygons, isosceles triangles, and parallelograms to work out unknown angles for a variety of 2-dimensional shapes.
Students use their knowledge of the angle between a tangent and radius property and the sum of the angles in a quadrilateral to work out unknown angles in a diagram and explain their workings.