Question

In the diagram, a building cast a 35-ft shadow and a flagpole casts an 8-ft shadow. If the the flagpole is 18 ft tall, how tall is the building? Round the the nearest tenth.​

Answer 1

Answer:  78.8 ft

Step-by-step explanation:

Similar triangles have proportional sides.

$\dfrac{\text{building shadow}}{\text{building height}}=\dfrac{\text{flagpole shadow}}{\text{flagpole height}}\\\\\\\dfrac{35}{\text{building height}}=\dfrac{8}{18}\\\\\\\dfrac{35\times 18}{8}=\text{building height}\\\\\\\dfrac{35\times 9}{4}=\text{building height}\\\\\\\dfrac{315}{4}=\text{building height}\\\\\\\boxed{78.75=\text{building height}}$