Angles (F)

All our angle facts are developed from there being 360^o in a circle. Thinking about it slightly differently, it means all the angles around a point will add up to 360^o.

From this, we can work out that angles on a straight line will add up to 180^o. Halving that again gives us 90^o, known as a right angle. This angle is so important that it even gets its own special symbol, a square. In a drawing, never assume an angle is 90^o unless the square is drawn in too.

It’s a good idea to arm yourself with the alphabet when dealing with angles – specifically you need C, F, X and Z. You also need to know the proper name for these types of angles – co-interior, corresponding, vertically opposite and alternate. C, F and Z angles occur where two or more parallel lines are crossed by another line.