For this week’s Math Blog Post, I drew a picture of how you can solve the height of a shadow. It doesn’t have to be just used for shadows, however.
Let me explain:
Step 1: Convert the feet into inches by multiplying by 12. Fred is 5 feet, 2 inches, which is 62 inches. The building is 50 feet, 2 inches, which is 602 inches. The building’s shadow is 60 feet, which is 720 inches. Remember that we are solving for Fred’s shadow.
Step 2: Put the inches into a formula:
Fred’s height Building’s height
__________ = _____________
Fred’s shadow Building’s shadow
The above formula is put into effect in the picture above. When you multiply 62 (Fred’s height) by 720 (Building’s shadow), you get 44,640.
Step 3: Divide.
Divide 44,640 by 600, and you get 74.4. But that’s not the answer. You must divide 74.4 by 12 to put it into feet and inches. 74.4 divided by 12 is 6.2, which is rounded to 6 feet, 2.5 inches.