Question

PLEASE ASAP

The area of a semicircle is 39.25 square kilometers. What is the semicircle's radius?
Use 3.14 for pi
__ kilometers

Answer 1

R=5

Explanation:

The area of a semi circle is 1/2(pi×R^2).

Since the area is given you would just work backwards.

Using 3.14 as "pi", you would have

39.25 = 1/2(3.14×R^2)

39.25*2 = 3.14*R^2

78.5 = 3.14* R^2

78.5/3.14 = R^2

25 = R^2

Then you would take the sqrt of R and 25

And the answer would come to 5 = R

R= radius

Answer 2

Answer -:

Given :

• Area of a semicircle = 39.25

Find :

• Radius of the semicircle

Solution :

`\small \tt{Area \: of \: a \: semicircle = (1)/(2) * \pi {r}^(2) }`

`\small\tt{39.25 = (1)/(2) * 3.14 * {r}^(2) }`

`\small\tt{39.25 * 2 = 3.14 * {r}^(2) }`

`\small\tt{78.5 \: = 3.14 * {r}^(2) }`

`\small\tt{ (78.5)/(3.14) = {r}^(2) }`

`\small\tt{ {r }^(2) = 25}`

`\small\tt{r = √(25) = 5 }`

`\small\tt{r = 5}`

Radius = 5

Hope it will help you