Angles

An angle measures a turn.

A builder laying bricks. Walls must meet at square corners.

Angles in buildings

Builders make walls meet at square corners. The corner is an angle. Angles measure how much something turns.

Right angles

A right angle is a quarter turn. It measures 90 degrees (90°). A small square marks a right angle.

Acute and obtuse

An acute angle is smaller than a right angle. An obtuse angle is bigger than a right angle. A straight line is 2 right angles: 180°.

Obtuse angles

This angle is more than a right angle. It is less than a straight line. It is obtuse.

Turning around a point

Angles are measured in degrees (°). A full turn is 360°, which is four right angles. Angles around a point add up to 360°.

Using a protractor

Put the centre of the protractor on the corner of the angle. Line up 0 with one arm and read where the other arm crosses. Order angles from smallest to largest: 30°, 50°, 90°, 140°.

What I learnt

I know an angle is a measure of turn.
I can identify right, acute and obtuse angles.