if a 3-foot -tall child casts a shadow that is 2 feet long, how tall is a telephone pole that casts a shadow that is 40 feet long?
Use a proportion.
3/2 = x/40
2x = 120
x = ?
3/2 = x/40
2x = 120
x = 60
To find the height of the telephone pole, we can set up a proportion between the height and the length of the shadow.
Let me explain how to do it step by step:
Step 1: Set up the proportion. We can write it as:
Height of the child / Length of the child's shadow = Height of the telephone pole / Length of the telephone pole's shadow
Step 2: Substitute the given values into the proportion. We know that the child is 3 feet tall with a shadow of 2 feet, so the proportion becomes:
3 / 2 = Height of the telephone pole / 40
Step 3: Solve for the height of the telephone pole. We can cross multiply by multiplying each side of the equation by 40:
(3/2) * 40 = Height of the telephone pole
Step 4: Simplify the equation:
60/2 = Height of the telephone pole
30 = Height of the telephone pole
Therefore, the height of the telephone pole is 30 feet.