Answer:
The height of the building is [tex]30\ ft[/tex]
Step-by-step explanation:
Let
x--------> the height of the building
y------> the long of the shadow of the building
m----> the height of Will
n-----> the long of the shadow of Will
we know that
By proportion
[tex]\frac{x}{y}=\frac{m}{n}[/tex]
we have
[tex]y=18\ ft[/tex]
[tex]m=5\ ft[/tex]
[tex]n=3\ ft[/tex]
substitute the values
[tex]\frac{x}{18}=\frac{5}{3}[/tex]
[tex]3*x=18*5[/tex]
[tex]x=30\ ft[/tex]
