How to Use the Circle Theorem where Opposite Angles in a Cyclic Quadrilateral Add Up to 180°
Question
What is the angle θ in the circle below?
Step-by-Step:
1
The opposite angles add up to 180°.
70° + θ = 180°
2
Subtract the known angle from 180°.
θ = 180° − 70° = 110°
Answer:
The angle θ is 110°.
This page was written by Stephen Clarke.
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