You can use the rules of parallel angles for these so the angles within the c shape add up to 180, this means that z=117 degrees (180-63=117) now you can workout what y is as opposite angles on a point are equal to each other therefore (5y-53) will equal 117
So now you can use this and rearrange to find y
So 5y-53=117
5y=117+53 as the sign changes
5y=170
y=170/5
y=34
