Geometry Level 1

Angle names Acute angle Web animation An acute angle is between 0 and 90 degrees *Task: Draw an example of an acute angle and label it on your whiteboard

Angle names Obtuse angle An obtuse angle is between 90 and 180 degrees *Task: Draw an example of an obtuse angle and label it on your whiteboard Website animation

Angle names Reflex angle A reflex angle is between 180 and 360 degrees *Task: Draw an example of a reflex angle and label it on your whiteboard

Angle names Right angle A right angle is 90 degrees

Angle names Right angle A right angle is 90 degrees

Angle names Straight angle A straight line is 180 degrees

Naming angles The angle is at B A BC

Guessing the angle size The clock is divided into 12 hours. One complete circle is 360 degrees. Each hour makes 30 degrees.

What angle do the hands of the clock make? 4 lots of 30 degrees. 120 degrees. OR the reflex angle is 240 degrees.

Guess the angle size OR

Measuring angles We use a protractor to measure angles.

There are two scales marked on your protractor

First decide if your angle is acute or obtuse This angle is acute

Read the acute scale.

The angle is 56 degrees.

This angle is obtuse.

Read the obtuse scale.

The angle is 124 degrees.