This powerpoint provides basic practice on the angle fact that the 'angles on a straight line add up to 180°'. It has slides that just cover straightforward calculations that can be used for mental arithmetic practice and others that require a problem solving approach. Equations can also be written and solved to find the answers. Some slides use three letter notation to identify angles.
GCSE 9-1 refs G3, G1, G6, A21, A17
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