A right angle is one quarter of a revolution. Four right angles make one revolution. A right angle measures 90°. We draw a small square in the corner of a right angle to show that it is equal to 90°. Right angles can be seen in our homes and school buildings.
We can make a right angle by folding a piece of paper in half and then in half again to make a 'corner'.
All of the angles we have seen so far are based on the revolution. Many other types of angles are compared to the right angle.