Solution:
The measure of the angle prescribed by the diameter of the semicircle on its circumference is 90°. So∠QPR = 90°.
Therefore, PQR is a right-angled triangle.
Area of a right-angled triangle is,
As PQR is a right-angled triangle, so by applying Pythagoras theorem, we get
The area of the semicircle is
Hence, Option (1) is the correct answer.