hello
to solve this question, let's make r the subject of formula
volume of a cone =
[tex]\begin{gathered} v=\frac{1}{3}\pi r^2h \\ 3v=\pi r^2h \\ \text{divde both sides by }\pi h \\ \frac{3v}{\pi h}=\frac{\pi r^2h}{\pi h} \\ r^2=\frac{3v}{\pi\text{h}} \\ r=\sqrt[]{\frac{3v}{\pi h}} \\ r=\text{radius} \\ v=\text{volume} \\ \pi=3.14 \\ h=\text{height } \end{gathered}[/tex]
b
volume = 125cm^3
radius (r) = ?
height (h) = 12cm
[tex]\begin{gathered} v=\frac{1}{3}\pi r^2h \\ r=\sqrt[]{\frac{3v}{\pi h}} \\ \pi=3.14 \\ r=\sqrt[]{\frac{3\times125}{3.14\times12}} \\ r=\sqrt[]{\frac{375}{37.68}} \\ r=\sqrt[]{9.95} \\ r=3.15\operatorname{cm} \end{gathered}[/tex]
the radius of the cone is equal to 3.15cm
