Given :
12 foot tall street light is making a 18 foot shadow at the same time a nearby building is making a 72 feet shadow.
To Find :
How tall is the building.
Solution :
Since, the time period is same so the angle angle of elevation is equal i.e the ratio of height of building is equal to height of shadow.
Let, height of building is h feet.
So,

Therefore, height of building is 48 feet.
Hence, this is the required solution.
STEP-BY-STEP EXPLANATION:
Given information:
Let x be the number
Mathematically, the statement can be translated below as

The next step is to represent it on a tape diagram
Answer:
The dimensions are 50 and 100 square foot
Step-by-step explanation:
Let x = length of fenced side parallel to the side that borders the playground
y = length of each of the other two fenced sides
Then, x + 2y = 200
<=> x = 200-2y
The Area = xy = y(200-2y)
The dimensions of the playground that will minimize the homeowner's total cost for materials when the area of the playground is maximum. He can cover more area but with the same cost.
The graph of the area function is a parabola opening downward.
The maximum area occurs when y = -200/[2(-2)] = 50
=> x = 100
So the dimensions are 50 and 100 square foot
Function would be f(x) = 5x+85
here, x= 15
5(15)+85 = 75+85 = $160