Question

What is the surface area?

Answer 1

Surface area of cone = 200π cm

Surface area of prism = 17.5 ft²

Explanation:

To find the slant height of cone

slant height l = √(r² + h²)

= √(8² + 15²) = 17

To find the surface area of cone

Surface are = πr² + πrl

= π*8² + π*8*17

= 64π + 136π

= 200π cm²

To find the surface area of prism

l = 4 ft

b = 1.5 ft and h = 0.5 ft

Surface area = 2(lb + lh + bh)

= 2[(4* 1.5) + (4*0.5) + (1.5*.5)

= 2(6 + 2 +0.7.5)

= 17.5 ft²

Answer 2

Surface Area of Cone = 200π cm^2

Surface Area of Right Prism = 17.5 ft^2

Explanation:

32. We are given a figure of a cone and we are to find its surface area.

We know that the formula for the S.A. of cone is given by:

Surface Area of cone =
`\pi r(r+√(h^2+r^2) )`

Substituting the given values in the above formula.

Surface Area of cone =
`\pi * 8(8+√(15^2+8^2) )` = 200π cm^2

25. We are to find the surface area of a right prism.

Surface Area of Right Prism = Base Perimeter × height + 2(Base Area)

Base Perimeter = 2(4 + 1.5) = 11 ft

Height = 0.5 ft

Base Area = 4 × 1.5 = 6 ft

Substituting these values in the above formula.

Surface Area of Right Prism = 11 × 0.5 + 2(6) = 17.5 ft^2