Question

Find the surfacs area of a cone wirh a slant height of 18in and a radius of 7in

Answer 1

Formula of the surface area of a cone is:
S.A = Area of base +
`(1)/(2)` × Perimeter of base × height of prism

S.A =
`\pi`r² +
`\pi`rl
=
`\pi`(7)² +
`\pi`(7)(18)
= 49
`\pi` + 126
`\pi`
= 175
`\pi` in² (in terms of
`\pi`)
= 549.7787 in²
≈ 550 in²