Lance is 5 feet tall. His shadow is 8 feet long.

At the same time of the day, a tree's shadow is 32 feet long. What is the height of the tree?

a) 20 feet b) 24 feet c) 29 feet d) 51 feet

To solve this problem, we have to set up a proportion, letting x represent the unknown height of the tree.

5 feet/8 feet = x feet / 32 feet

To solve this equation, we have to use cross products, or the multiplication of the numerator of one fraction by the denominator of the other fraction, and setting them equal to one another.

5 (32) = (8) x

When simplified, as we multiply the numbers on both sides of the equations, we get the equation:

160=8x

20=x

Therefore, if a tree's shadow is 32 feet long, the height of the tree is a) 20 feet.