I think that it’s 22.28 cm^2.
The diameter is 4, meaning that the radius is 2. Pi r ^ 2 is what is the formula to find the area of a circle, and 2 squared is 4. 4 * 3.14 is 12.56. 12.56/2 is 6.28. 6.28 + 16 (4 * 4 is 16, which is the area of the square) is 22.28. I could be wrong but this is how I solved it.