Lesson

Can you estimate the size of an angle? This can be useful skill when checking our measurements are reasonable.

Estimate the size of the angle made by the mountains at the centre.

A

Greater than 90\degree

B

Less than 45\degree

C

Equal to 180\degree

Worked Solution

Idea summary

If we remember some important angles, we can use those to estimate other angles.

This video shows you how to use a protractor to measure acute, obtuse, and reflex angles.

What is the angle being measured by this protractor?

Worked Solution

Idea summary

The protractor has two sets of numbers, make sure you are reading off the value of the angle from the correct set.