Question

a barn casts a shadow that is 12 meters long while a tree in the yard casts a shadow that is 8 meters long. how long is the tree if the barn is 20 meters long?

Answer 1

Using proportion...

length of barn length of tree
-------------------------------- = --------------------------------
length of barn's shadow length of tree's shadow

20 x
---- = ---
12 8

Using cross-multiplication...

20 x 8 = 12x
160 = 12x
x = 13 1/3 or 13.3333

The tree is 13 1/3 meters long.