Question

Find the surface area of cone with a diameter of 12cm and height of 18cm in terms of pi

Answer 1

Surface area of the cone = 149.4π cm²

Explanation:

Surface area of the cone is found using the radius and height as,

`\mathrm{SA}=\pi r(r+\sqrt{\left(h^(2)+r^(2)\right)}`

From the given diameter, we can find the radius as,

radius =
`$(12)/(2)` = 6 cm

height = 18 cm

`S A=\pi * 6(6+\sqrt{\left(18^(2)+6^(2)\right)}`

`\mathrm{SA}=6 \pi(6+√((324+36)))`

`$\mathrm{SA}=6 \pi(6+√((360)))`

`\mathrm{SA}=6 \pi(6+18.9)`

`\mathrm{SA}=6 \pi(24.9)`

`S A=149.4 \pi \mathrm{cm}^(2)`