The shadow of a woman standing 10 ft from a streetlight is 2.5 ft long. If the streetlight is 30 ft tall, how tall is the woman

Question

The shadow of a woman standing 10 ft from a streetlight is 2.5 ft long. If the streetlight is 30 ft tall, how tall is the woman

Answer 1

This is a problem of similar triangles

 

Construct the triangles;

 

Draw a horizontal line ABC ; AB = 2.5' AND BC = 10'

 

at C erect a vertical line CD = 30' tall

 

Connect A to D with a straight line.

 

erect a vertical line at B, where it cuts AD is E

 

EB/DC = AB/AC ;  EB = height of woman = DC*AB/AC = 30*2.5/12.5 = 6 feet