Question

Two similar cylinders are shown in the image below.

http://i1215.photobucket.com/albums/cc513/wattpadbookcoverstry/Math/image0034e848874.gif

If the smaller cylinder has a lateral area of approximately 302 square meters, what is the approximate lateral area of the larger cylinder?

1,618.5 square meters

528.5 square meters

924.9 square meters

98.6 square meters

Answer 1

What is the formula to find the lateral area of a cylinder?

Answer 2

LA = 2 pie r h

Answer 3

2 pie? :P Like this? http://micropipes.com/blog/wp-content/img/2008_rhubarb_pies.png
just kidding :P

And what's the ratio for the two cylinders? (Hint: Height)

Answer 4

Uh 28?

Answer 5

Height of the small cylinder : Height of the big cylinder

Answer 6

16:28

Answer 7

Great!
Now, do you agree that
Height of the small cylinder/Height of the big cylinder
Circonference of the base of the small cylinder/ Circonference of the base of the big cylinder
Radius of the base of the small cylinder/Radius of the base of the big cylinder
all these ratios are the same, given that both cylinders are similar?

Answer 8

Yeah

Answer 9

Alright. Do you also agree that, if I have a square, which dimensions are 2x2 (Area: 4), and I have another square, which dimensions are 4x4(16)
Its ratio is 2:4 (Small square:Big square)
And that its area ratio is 4:16 OR, it's ratio, squared? :D (2 ^2 : 4^4)

Answer 10

If the area ratio is the ratio squared, what would be this problem's area ratio? Ratio is (16:28)

Answer 11

It would be 16^2 : 28^2
256 : 784
Small cylinder's area is ~302
You would have
302 : x

Find x :)

It would be 924.875m2

Answer 12

@zepp so approx it would be 924.9?

Answer 13

Yeah

Answer 14

oh ok, thanks

Answer 15

yw :)