Estimate acute and obtuse angles using the standard unit of degrees

I can estimate acute and obtuse angles using the standard unit of degrees.

Download all resources

Share activities with pupils

New

Year 5

Estimate acute and obtuse angles using the standard unit of degrees

I can estimate acute and obtuse angles using the standard unit of degrees.

Download all resources

Share activities with pupils

These resources will be removed by end of Summer Term 2025.

Switch to our new teaching resources now - designed by teachers and leading subject experts, and tested in classrooms.

View new resources

Slide deck

Download slide deck

Skip slide deck

Lesson details

Key learning points

You can estimate angles by comparing to a right angle of 90 degrees.
Half a right angle is 45 degrees.
One and a half right angles are 135 degrees.

Keywords

Estimate - To estimate is to find a value that is close enough to the right answer, usually with some thought or calculation involved.
Degree - A degree is a unit of measure for angles.

Common misconception

Pupils significantly over or under-estimate the size of angles, particularly when the initial line of the angle is not vertical or horizontal.

Encourage pupils to rotate the angle so that one of the lines is vertical or horizontal, or if possible, look at the angle from a different point of view which may help to view a line of the angle from a vertical or horizontal position.

Spend time moving on from the use of angle tools to estimate angles to estimating only with the two given lines. Pupils should look to develop a sense of different angle sizes in different orientations.

Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).