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

Respuesta :

halljayden538

Answer:

R=5

Step-by-step 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

spbankingandsscserie

Answer -:

Given :

  • Area of a semicircle = 39.25

Find :

  • Radius of the semicircle

Solution :

[tex] \small \tt{Area \: of \: a \: semicircle = \frac{1}{2} \times \pi {r}^{2} }[/tex]

[tex] \small\tt{39.25 = \frac{1}{2} \times 3.14 \times {r}^{2} } [/tex]

[tex] \small\tt{39.25 \times 2 = 3.14 \times {r}^{2} } [/tex]

[tex] \small\tt{78.5 \: = 3.14 \times {r}^{2} } [/tex]

[tex] \small\tt{ \frac{78.5}{3.14} = {r}^{2} } [/tex]

[tex] \small\tt{ {r }^{2} = 25} [/tex]

[tex] \small\tt{r = \sqrt{25} = 5 } [/tex]

[tex] \small\tt{r = 5} [/tex]

Radius = 5

Hope it will help you

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