Answer:
x= 5
Explanation:
Since RQ= PQ,
3x= 15
Divide both sides by 3:
x= 15 ÷3


Let SP= x
RS= SP= x (given)
Let SQ= y
Applying Pythagoras' Theorem,
In triangle QRS
(RQ)²= (RS)² +(SQ)²
(RQ)²= x² +y²

In triangle QPS
(PQ)²= (SP)² +(SQ)²
(PQ)²= x² +y²

Thus, RQ= PQ.