In the diagram below, a 5 foot tall girl is standing 24 feet from a lamp post at night. If her shadow from the light is 8 feet long, what is the height of the lamp post?

Question

perl · Answer

|dw:1428730831541:dw|

perl · Answer

by similarity of triangles
$$\Large{
\frac{h}{24+8} = \frac{5}{8}


}$$

anonymous · Answer

@perl 
I'm confused

perl · Answer

|dw:1428731329454:dw|

perl · Answer

they are similar because they share that corner angle, and both have right angles. 
AA similarity postulate

perl · Answer

that might be a theorem now that i think about it.