In this activity, we’ll take a look at types of angles.
A right angle is an angle that is equal to 90°.
Here is a right angle.
We can see it’s marked with a rectangle corner marker.
If you see an angle marked with a square or rectangle, it’s a right angle.
An acute angle is an angle that is smaller than 90°.
Here is an acute angle.
An obtuse angle is an angle that is larger than 90°.
Here is an obtuse angle.
Let’s look at an example question.
Example
How many of the angles shown below are acute?
Answer
An acute angle is smaller than a right angle.
Three of the triangles shown are acute (smaller than a right angle)
