Angles-In-Quadrilaterals Wjec-Eduqas Foundation

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Exam code:C300

Angles in quadrilaterals

What are the angle properties of quadrilaterals?

The four interior angles inside any quadrilateral add up to 360°
If the quadrilateral is a square or a rectangle then all the angles are equal to 90°
You can use any symmetries of the quadrilateral to identify other equal angles
- For a parallelogram or rhombus, opposite angles are equal
- For a kite, one pair of opposite angles are equal

Examiner Tips and Tricks

Find all the missing angles that you can using the angles that are given to you in a question
- They might not seem to help you straight away but having more angles will lead you to find the angle you need

Worked Example

The diagram below shows an irregular quadrilateral. Find the value of $y$ .

Find the missing angle inside the quadrilateral using the rule ‘angles in a quadrilateral add up to 360°

First, add together the three given angles

$97 space plus space 115 space plus space 85 space equals space 297$

Subtract the answer from 360°

$table row cell 360 space minus space 297 space end cell equals cell space 63 space end cell end table$

Add this to the diagram

Quadrilateral angle properties worked example working

Angles on a straight line add up to 180°, so subtract the answer from 180°

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Maths Gcse Wjec-Eduqas Foundation

Angles-In-Quadrilaterals Wjec-Eduqas Foundation