How_To_Be_Good_At_Math

232 GEOMETRY •^ RIGHT ANGLES

Right angles

Right angles are important angles in geometry. In fact, they

are so important they get their own special symbol!

A full turn is all the way round to where

the line started, which is 360°. A full turn

is made up of four right angles.

A three-quarter turn is 270°. It's made up

of three right angles.

A half turn is 180°. It's also called a

straight angle, because it makes a

straight line. You can also think of a straight

angle as two right angles.

A quarter turn like this is 90°. We call it a

right angle. When we mark a right angle,

we make a corner symbol, like this:. We

don't have to write "90°" next to the symbol.

0°

0° 360°

90°

90° 90°

180°

270°

270° 270°

Turns can be

clockwise, like this,

or anticlockwise

Right angle

symbol

270° 90°

180°

180° 180°

When you draw the right

angle symbol on an

angle, you don’t need to

write “90º” next to it.

0°

232_233_right_angles_angle_sizes.indd 232 29/02/2016 18:05