Question

MEDAL!!!
What are the lateral area and the surface area of the cone shown below? Round the answer to the nearest tenth. The figure is not drawn to scale.
A. LA=829.4FT^2;SA=1,209.5FT^2
B. LA=829.4FT^2;SA=3,041.1FT^2
C. LA=380.1FT^2;SA=1,209.5FT^2
D. LA=380.1FT^2;SA=3,041.1FT^2

Answer 1

Same with the first cone except they give you r and l, you need to find h.

Use the Pythagorean Theorem to solve for h, then use the equation for a cone to solve for the LA and SA.

r = 11 feet
l = 24 feet
\[r^{2} + h^{2} = l^{2}\]

\[SA = \pi r ^{2} + \pi r l\]
\[LA = \pi r l\]

Answer 2

11^2+H^2=24^2

Answer 3

121+H^2=576

Answer 4

-121

Answer 5

H^2=455

Answer 6

Yes, now take the square root to find h.

Answer 7

21.3

Answer 8

yes that's correct

Answer 9

WHATS THE NEXT STEP

Answer 10

now you have r, h, and l.

You are asked to find SA and LA.

Answer 11

HOW DO I DO THAT?

Answer 12

Use the SA and LA equations.
\[SA = \pi r^{2} + \pi r l\]
\[LA = \pi r l\]

Answer 13

ok so pi(11)+pi(11)l

Answer 14

don't forget to square the r for the area of the circle

Answer 15

sorry forgot square the r?

Answer 16

pi (11) ^2 + pi (11) l

Answer 17

379.94+34.54 l

Answer 18

multiply 34.54 by your value for l

Answer 19

L is 24

Answer 20

SA = pi (r)^2 + pi (r)(L)
LA = pi (r) (L)

Answer 21

828.96

Answer 22

I got SA = 1209.51 and LA = 829.38