Unit 3: Shrinking and Stretching
Hwk # 10 – using shadows (Inv. 4.4)
Name _____________________________
For each problem, make a sketch to depict your shadow problem.
1. A 6 ft. man is standing next to a large cactus in the desert. The cactus and the
man are perpendicular to the ground. The sun’s rays strike the cactus and the
man at the same angle forming two similar triangles. If the man casts a
shadow that is 2 ft. long and the cactus casts a 5 ft. shadow, how tall is the cactus?
2. The shadow of a goalpost on a football field is 20 feet long. A football player who is 5 feet tall stands
next to the goalpost and casts a shadow 3 feet long. How tall is the goalpost?
3. A man who is 74 inches tall stands beside a palm tree. The length of the man’s shadow is 32 inches.
The palm tree’s shadow is 80 inches long. How tall is the palm tree?
Stretching and Shrinking
Homework #10
4. The Washington Monument is the tallest structure in Washington, D.C. At the same time the
monument casts a shadow that is about 500 feet long, a 40 – foot flagpole nearby casts a shadow that
is about 36 feet long. Find the approximate height of the monument.
5. Darius uses the shadow method to estimate the height of a flagpole. He finds that a 5-foot stick casts
a 4-foot shadow. At the same time, he finds that the flagpole casts a 20 foot shadow. Estimate the
height of the flagpole.
Stretching and Shrinking
Homework #10