# I ended up applying all the circle theorem's I knew. Can you help me figure this out?

##### 1 Answer

Mar 8, 2018

#### Answer:

x=80

#### Explanation:

You only need one circle theorem for this solution:.

The angle at A (BAC) is half the size of

('The angle subtended by an arc at the centre is twice the angle subtended at the circumference.' *Source: BBC Bitesize* )

Then some basic geometry:

All angles around a point add up to 360°

So **internal** angle at P (CPB) can be written as

And all angles in a quadrilateral add up to 360°

So we can form an equation:

By rearranging for