Answer: $494.55
Explanation:
Given : A stained glass window is going to be installed in a semi-circular opening, which is above a 30 inch wide door.
Then the diameter of the semi-circular glass = 30 inches
Also, the radius of the glass =

We know that the area of a semicircle is given by :-

Then , the area of the stained glass window :-

The cost of window will be :-

Hence, the cost of window = $494.55