math
posted by Anonymous .
A building casts a 20 ft shadow. At the same time, a nearby 10 ft maple tree casts a shadow of 8 ft. What is the height of the building?

same thing as below.
10/8 = x/20
5/4 = x/20
4x = 100
x=25
Plugging in, 25/ 20 = 10 /8
= 5/4 = 5/4