Question

An arc length is a fractional part of the

circumference of a circle. The area of a
sector is a fractional part of the area of a
circle

The stained glass circle- head
the window has a 2 -inch wide
frame. The grills divide the
semicircular glass plane into
four congruent regions

Using detailed steps, describe your
solution to the problems below

Your steps should be clear enough so that
any geometry student can complete
them
A. Find the area of the blue region
B. Find the perimeter of the outer window
frame

Answer 1

Each of the 4 sectors have an area:

• πR²/8 - πr²/8, where
• R = 28/2 - 2 = 12 in
• r = 6/2 = 3 in

Find the area:

• A = π/8(12² - 3² ≈ 53 in²

Outer perimeter of the frame:

• P = d + πd/2 =28( 1 + π/2) ≈ 72 in