Didn't answer all because I got lazy and I think you should try and do the rest yourself. Did this in 5 mins, try putting more effort into your homework. This is basic mathematics.
Answer:
9.82 feet
Step-by-step explanation:
the perimeter of the window is the circumference of a semi-circle with a diameter of 5
P = (πd)/2 (divided in half because it's only half a circle)
P ≈ 3.14(3.5) which is approx 11
11 is closest to 9.82