Question

The radius of the base of the cone is an 5cm

and slant height is 9cm
Find out its total
surface area
area.​

Answer 1

The total surface area of cone is 70π cm² or 219.9 cm².

Explanation:

Given that the formula of total surface area of cone is T.S.A = πr² + πrl where r represents radius and l is slant height. So you have to substitute the values :

`t.s.a = \pi {r}^(2) + \pi{r}l`

`let \: r = 5 \: , \: l = 9`

`t.s.a = \pi {(5)}^(2) + \pi(5)(9)`

`t.s.a = 25\pi + 45\pi`

`t.s. a = 70\pi \: or \: 219.9 \:`