Properties of Quadrilaterals: Step-by-Step Example
23 October 2026
Quadrilaterals are shapes with four sides and four angles. To solve questions about their angles, it helps to know a key fact about their properties.
Find the missing angle in a quadrilateral
A quadrilateral has three angles: 90°, 85°, and 95°. What is the fourth angle?
First, remember that all the angles in a quadrilateral add up to 360°.
Add the three angles you know: 90° + 85° + 95° = 270°.
Now subtract this from 360°: 360° - 270° = 90°.
The correct answer is 90°.
After working through this example, your child will recognise how to find a missing angle in any quadrilateral. The next step is to practise similar questions to build confidence with properties of quadrilaterals.
