Question

Semi circle ! Please help. URGENT

Answer 1

Explanation:

1)

What is the radius and the circumference of the semicircle.

Diameter of semi circle = 12 in

Radius = 12 /2 = 6 in

Circumference of semi circle = πr + 2r

= 3.14 × 6 + 2 × 6

= 18.84 + 12

= 30.84 inches

2) What is the area of each semi circle?

when diameter is 5 in

Radius = 5/2 = 2.5 in

Area of semicircle =
`(1)/(2) \pi {r}^(2)`

`\rightarrow \sf(1)/(2) * 3 .14 * 2.5 * 2.5 \\ \\ \rightarrow \sf (19.625)/(2) \\ \\ \rightarrow \sf9.82 \: {in}^(2)`

When the diameter is 6.4 in

Radius = 6.4/2 = 3.2 in

Area of semicircle =
`(1)/(2) \pi {r}^(2)`

`\rightarrow \sf(1)/(2) * 3 .14 * 3.2 * 3.2 \\ \\ \rightarrow \sf (32.1536)/(2) \\ \\ \rightarrow \sf16.08 \: {in}^(2)`