This problem can be a bit confusing, so let's break it down:
First, let's take the area of the square (A = b · h):
A = 15 · 15
A = 225 cm²
Now comes the confusing part:
We can tell that the non-shaded area is 1/4 of a circle, so, if we take 1/4 of the area of a circle, we can subtract its area from the area of the square:
A = πr²
A = 15²π
A = 225π
1/4 A = 225π / 4
New Area = 56.25π
Or... about 176.7
Since we have both of the areas, all we have to do is subtract:
225 - 176.7 =
48.3.
Your final answer is 48.3 cm²