Question

Find the perimeter of the window. Round your answer to the nearest tenth.

Answer 1

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.