Aman who is 6 feet tall casts a shadow that is 4 feet long. at the same time, a nearby flagpole casts a shadow that is 18 feet long. how tall is the flagpole?

For this case we can use the similarity of triangles to solve the problem.
 We then have the following relationship:
 x / 6 = 18/4
 From here, we clear the value of x.
 We have then:
 x = (18/4) * (6)
 x = 27 feet
 
 the flagpole is 27 feet tall

Idon’t know how to do that