The four types of angle you should know are acute, obtuse, reflex and right angles. When you are estimating the size of an angle, you should consider what type of angle it is first.

What kind of angle is this?

Acute angle

Obtuse angle

Reflex angle

What kind of angle is bigger than ?

Right angle

Estimate the size of this angle

Estimate the size of this angle.

What is the size of this angle?

What is the sum of the angles in any triangle?

A quadrilateral shape has angles of , and . What is the size of the fourth angle?

What is the size of each angle in an equilateral triangle?

There isn't enough information in the question

The size of two of the three angles in a triangle are and . What is the special name given to this triangle?

Isosceles triangle

Equilateral triangle

Scalene triangle

The biggest angle in an isosceles triangle is . What are the size of the other two angles?