The 7 cm side of the rectangle also serves as the radius of the circle
The problem wants us to take the area of the rectangle and subtract it by each of the 3 semicircles
The area of a full circle is:
SEMICIRCLE:
So the area of a semicircle is half of that:
All 3 of these semicircles have the same area so once we find the area of one, all we have to do it multiply it by 3:
The area of one semicircle is 38.465 so 3 of them would be 115.395cm
RECTANGLE:
The area of a rectangle is equal to length • width
The width is given as 7cm and we can find the length by remembering that the radius of each semicircle is 7cm and since there are 3 semicircles we know the length of the rectangle is 21 cm
Making the area of the rectangle 7cm • 21cm which equals 147cm
Now we take 147cm and subtract it by 115.395cm and we are left with 31.605cm^2 I believe
My Best Guess: 31.605cm ^2