Explanation:

Given \(\bigtriangleup\) isosceles PQ = QT, SRQ = 35^o

TPQ = 20^o

PQR = is a straight line

Since PQ = QT, angle P = angle T = 20^o

Angle PQR = 180^o - (20 + 20) = 140^o

TQR = 180^o - 140^o = 40^o < on a straight line

QSR = 180^o - (40 + 35)^o = 105^o

TSR = 180^o - 105^o

= 75^o