#4.1A
distinguish between acute, obtuse, reflex and right angles
#4.1B
use angle properties of intersecting lines, parallel lines and angles on a straight line
Angles at a point, vertically opposite angles, alternate angles, corresponding angles, allied angles
#4.1C
understand the exterior angle of a triangle property and the angle sum of a triangle property
#4.1D
understand the terms ‘isosceles’, ‘equilateral’ and ‘right-angled triangles’ and the angle properties of these triangles