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The formula for the volume of a cone is equal v=1/3
\pir²h,

The formula for the volume of a cone is equal v=1/3\pir²h,-example-1
User HieroB
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1 Answer

4 votes

hello

to solve this question, let's make r the subject of formula

volume of a cone =


\begin{gathered} v=(1)/(3)\pi r^2h \\ 3v=\pi r^2h \\ \text{divde both sides by }\pi h \\ (3v)/(\pi h)=(\pi r^2h)/(\pi h) \\ r^2=\frac{3v}{\pi\text{h}} \\ r=\sqrt[]{(3v)/(\pi h)} \\ r=\text{radius} \\ v=\text{volume} \\ \pi=3.14 \\ h=\text{height } \end{gathered}

b

volume = 125cm^3

radius (r) = ?

height (h) = 12cm


\begin{gathered} v=(1)/(3)\pi r^2h \\ r=\sqrt[]{(3v)/(\pi h)} \\ \pi=3.14 \\ r=\sqrt[]{(3*125)/(3.14*12)} \\ r=\sqrt[]{(375)/(37.68)} \\ r=\sqrt[]{9.95} \\ r=3.15\operatorname{cm} \end{gathered}

the radius of the cone is equal to 3.15cm

User Juan Pablo Rinaldi
by
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