Question

Radius of cones base and the volume of the cone?

Answer 1

radius: 21 cm

V= 9702 cm³

1) We know the Base area of a cone is 1,386 u². We know the base of a cone is a circle.

`\begin{gathered} A=\pi r^2 \\ \\ 1,386=(22)/(7)r^2 \\ \\ (22)/(7)r^2=1386 \\ \\ 7\cdot (22)/(7)r^2=1386\cdot \:7 \\ \\ 22r^2=9702 \\ \\ (22r^2)/(22)=(9702)/(22) \\ \\ r^2=441 \\ r=21 \end{gathered}`

Note that we have used the given approximation to pi.

2) Now, for the volume, we can write the following notice that r=h

`\begin{gathered} V=(1)/(3)\pi r^2h \\ \\ V=(1)/(3)((22)/(7))(21)^2(21) \\ \\ V=9702\:cm^3 \end{gathered}`