What is the approximate surface area of the larger cone?

1544.4 square yards

978.5 square yards

2,162.3 square yards

1,103.1 square yards

Question

What is the approximate surface area of the larger cone?

1544.4 square yards

978.5 square yards

2,162.3 square yards

1,103.1 square yards

anonymous · Answer

attachment

ash2326 · Answer

The two cones are similar, so their dimensions would be in the same ratio
Let the larger cone's radius be x yards. so
$$\frac{x}{8}=\frac{42}{30}$$
Can you find the larger cone's radius?

anonymous · Answer

its 9 not 8

ash2326 · Answer

Sorry then it's
$$\frac x 9=\frac{42}{30}$$

anonymous · Answer

x     42
- =  --
9     30

42
-- = 1.4
30

ash2326 · Answer

Good, find x?

anonymous · Answer

wouldnt i multiply 9 by 1.4

anonymous · Answer

by multiplying 9 by 1.4 it equals 12.6

ash2326 · Answer

Yeah x=12.6
I think you can find the surface area now, can't you?

anonymous · Answer

pi times radius times slant + pi times radius^2

anonymous · Answer

3.14 times 12.6 times 42 + 3.14 times 12.6^2
1661.668 + 498.5064

anonymous · Answer

2160.1744

ash2326 · Answer

Good work

anonymous · Answer

but thats not one of the choices

ash2326 · Answer

Use 22/7

ash2326 · Answer

You'll get 2162.16 square yards