Question

taking a test- Which expression represents the surface area of the cone? A cone with diameter 12 inches, height 8 inches, and slant height 10 inches. S A = pi r l + pi r squared (pi) (6) (10) + (pi) (6 squared) (pi) (8) (10) + (pi) (8 squared) (pi) (12) (10) + (pi) (12 squared) (pi) (10) (12) + (pi) (10 squared)

Answer 1

`SA = \pi (6) * 10+\pi ( 6)^2`

Explanation:

The surface area of a cone is given by

`SA = \pi rl +\pi r^2`

r is the radius and l is the slant height.

The diameter is 12 inches, the radius is 12/2 = 6 inches.

The slant height is 10 inches.

`SA = \pi (6) * 10+\pi ( 6)^2`

Answer 2

SA of cone =
`(\pi )(6)(8) + (\pi )(6)^2`

Explanation:

Surface Area of cone =
`\pi rh+\pi r^2`

Where r = 6 inches (Diameter = 12 inches) , h = 8 inches (We'll not consider the slant height)

SA of cone =
`(\pi )(6)(8) + (\pi )(6)^2`