Question

Will give MEDAL for help in geometry!


A five-foot Prep casts a shadow that is 40 feet long while standing 200 feet from a streetlight. How high above the ground is the lamp?

Answer 1

@agent0smith @DanJS

Answer 2

hi

Answer 3

did you draw a picture of the scene ?

Answer 4

OH! so now I see my mistake!

Answer 5

Assuming the light is at right angle to the ground, there is a 5 ft thing 200 ft away from it

Answer 6

But how did the 40 ft shadow become a measurement of the leg?

Answer 7

This is a side view, the bottom is the ground, the shadow is cast 40ft along the ground

Answer 8

ok

Answer 9

Here's a continuation of the problem:

How far from the streetlight should the Prep stand, in order to cast a shadow that is exactly as long as the Prep is tall?

Answer 10

So they want a 5 ft shadow.. just have to change around how far away from the lamp they standing...

Answer 11

would h = 25?

Answer 12

similar triangles
\[\frac{ 40 }{ 5 }=\frac{ 240 }{ h }\]

Answer 13

The larger triangle is 240 length...

Answer 14

how would it be 240 in length?

Answer 15

The small triangles legs are 40 and 5
The large triangle legs are h and (200 + 40)

Answer 16

oh i forgot to include them both

Answer 17

h = 30ft

Answer 18

right

Answer 19

for the second problem would the distance be 25?