MathematicsCode 4029
Angles
What this topic asks you to be able to do
- Work out unknown angles and give simple reasons for them, using these geometrical facts: the sum of the angles round a point = 360°; the sum of the angles at a point on one side of a straight line = 180°; angles that are vertically opposite are equal; in a triangle, the angle sum = 180°; in a quadrilateral, the angle sum = 360°.
- Work out missing angles and give geometric reasons for angles formed between parallel lines, where corresponding and alternate angles are each equal, and co-interior angles total 180° (supplementary).
- Know the angle properties of polygons, both regular and irregular, and use them. Three-letter notation for angles, e.g. angle ABC, must be understood. Reasons for answers should use correct geometrical terms. This covers interior and exterior angles and the angle sum.