Answer:
Part a)

Part b)

Explanation:
step 1
we know that
The diameter of the circle divide the circle into two equal parts
so
PM=MQ
Applying the Intersecting Chord Theorem (When two chords intersect each other inside a circle, the products of their segments are equal)


we have


substitute



step 2
Find the value of PQ
we know that

so


we have

substitute
