b = 17
Explanation:
Step 1:
Given PQ = QR in triangle PQR.
So, triangle PQR is an isosceles triangle.
Hence,
– – – – (1)
Step 2:
Let us consider two triangles PQS and SQR.
(given angle)
PQ = QR (given side)
(angle proved in equation (1))
(by ASA congruence criterion)
Hence by corresponding parts of congruence triangles,
⇒ PS = SR
⇒ PS = 17
⇒ b = 17
Hence the value of b is 17.