[tex]\bf \textit{area of a circle}\\\\ A=\pi r^2~~ \begin{cases} r=radius\\[-0.5em] \hrulefill\\ A=78.5 \end{cases}\implies 78.5=\pi r^2\implies \cfrac{78.5}{\pi }=r^2 \\\\\\ \sqrt{\cfrac{78.5}{\pi }}=r\implies 4.9987\approx r[/tex]
Answer:
5 inches
Step-by-step explanation:
Given : A circle with an area of 78.5 cubic inches .
To Find: What is the radius of a circle with an area of 78.5 cubic inches?
Solution :
Formula of area of circle:
[tex]\pi r^{2}[/tex]
where r is the Radius of circle
Since we are given thet the area of circle 78.5 cubic inches
Using the above formula :
[tex]78.5=\pi r^{2}[/tex]
Using π =3.14
[tex]78.5=3.14*r^{2}[/tex]
[tex]\frac{78.5}{3.14} =r^{2}[/tex]
[tex]25=r^{2}[/tex]
[tex]\sqrt{25} =r[/tex]
[tex]r=5[/tex]
Thus , 5 inches is the radius of a circle with an area of 78.5 cubic inches
