Posted by Keith on Friday, June 24, 2011 at 4:30am.
If a person is 66 inches tall is standing 15 feet away from a streetlight. If the person casts a shadow 84 inches long, how tall is the streetlight?

College Algebra  Keith, Friday, June 24, 2011 at 4:31am
Sorry, the question is "A person is 66 inches tall is standing 15 feet away from a streetlight. If the person casts a shadow 84 inches long, how tall is the streetlight?"

College Algebra  drwls, Friday, June 24, 2011 at 7:15am
Let X be the streetlight height.
84 inches is 7.00 feet.
66 inches is 5.50 feet.
Draw a figure with a light ray passing from the light, skimming the top of the person's head and striking the ground at the end of the shadow.
Because of similar triangles,
H/(15 + 7) = 5.5/7
H = 22*(11/14) = 17.29 feet