Concept

Angles can be classified according to the size of the angle.
Angles are formed by two rays that have the same endpoint.

Rule

Example

Choose the correct answer.
Which angle is smaller than a right angle?

Solution

1. A right-angle measures 90°.

2. An acute angle measures greater than 0°, but less than 90°.

Answer: An acute angle is smaller than a right-angle.

Pre-requisite Skills

Classify Angles (4.10.2)