A building casts a shadow 100m long. At the same time, a nearby pole is 4m high and casts a shadow 8m long. What is the height of the building?

Question

Round your answer to the nearest tenth, if necessart

Answers:

A. 200m

B. 0.5m

C. 50m

D. 800m

Answer 1

This is a ratio problem using two similar triangles. We can determine that these are similar triangles because their angles are all the same. The shadows of the building and pole are proportional to the heights the two objects.

ShadowBuilding/ShadowPole = HeightBuilding/HeightPole

Let x = the height of the building

100/8 = x/4

Cross multiply:

100(4) = 8x

400= 8x

50 = x

 

The height of the building is 50m

Answer 2

Let's say the height of the building is h m

 

Height of building / length of its shadow = height of pole / length of its shadow

h/100=4/8  Now cross multiply

8h = 400

h= 400/8 = 50 m

Therefore, C is the right answer.

 

 

 

 

Answer 3

4/8 = b/100

 

I bet you can get it from here!