## Content description

Estimate, measure and compare angles using degrees. Construct angles using a protractor (ACMMG112)

Source: Australian Curriculum, Assessment and Reporting Authority (ACARA)

### Types of angles

When we estimate and compare angles, we need to have something to compare them to. We begin with a revolution, and later we use a right angle as the angle of comparison.

#### Revolution

We start with a full revolution. A full turn around the vertex is 360°.

#### Straight angle

A straight angle is half a revolution; the arms of the angle make a straight line. A straight angle measures 180°.

Straight line 180°

Detailed description