Since this is a half of a circle, we can find the circumference of a circle and then divide it by 2. The circumference of a circle is C = pi * D We know that pi is 3.14 and the diameter of the circle is 3. Plug in for the variables and find the circumference. C = 3.14*3 C = 9.42 Next, divide the circumference by 2: 9.42/2 = 4.71 The perimeter of the window is 4.71 square feet. Hope this helps.
