PPP, Q Q\,Q and R R\,R are points on the circumference of a circle, centre OOO. XRY XRY\,XRY is a tangent to the circle at point RRR.
Angle PQR=55∘PQR = 55^\circPQR=55∘ Angle PRQ=72∘PRQ = 72^\circPRQ=72∘ Angle QRY=x∘QRY = x^\circQRY=x∘
Find the value of xxx.
Give reasons for each stage of your working.
