How do you find the perimeter of the window to the nearest tenth. Half the widows radius is 20.

Step-by-step explanation:

1) The perimeter is the sum of the lengths of the straight edge (the diameter of the semicircle) and the length of the arc of the semicircle.

The circumference of a 4 ft circle is

 π*diameter = π*4 ft ≈ 12.566 ft

The semicircle will have a length that is half that, 6.283 ft. When this length is added to the diameter, the perimeter is found to be

 Perimeter = 4 ft + 6.283 ft ≈ 10.3 ft.

2) The area of a circle is given by the formula

 A = (π/4)d²

For a diameter of 15 inches, the area is

 A = (π/4)(15 in)² = 56.25π in²

 A ≈ 176.7146 in²

The area of the circle is about 176.71 in².

answer: 177/8

step-by-step explanation: