Question

hey i have no idea how 2 answer this problem, help please! here it is: A 30 foot tall tree casts a shadow that is 20 feet long. At the same time, a building casts a shadow 50 feet long. Write a proportion to find the height of the building. HELP

Answer 1

no genius here but ill try to help

Answer 2

I find pictures to help a lot with this..

Answer 3

The ratio of height to the shadow will be same at a time for different objects in a particular location.
hence as the ratio for the tree is 3 : 2 it will be same for the building too....
Hence the height of the building will be 75 feet

Answer 4

You can set these problems up like a ratio. Keep the units the same on both sides (height on top/shadow on bottom)

30/12=x/50
Now cross multiply
30*50=12x

Solve for x
:)

Answer 5

You're given to assume that the angles made by the shadows are the same.. Therefore you have two similar triangles, and the ratio of their sides will be equal.

Answer 6

And no, that's not to scale since I made the shadows too long before I read the numbers you were working with.

Answer 7

thanks i got it =)