He saw a trash can that was 3 feet tall . then he saw a lamppost that's was 4times as tall as trash can . how tall was the lamppost ?

The lamp post is 12 feet tall.

Step-by-step explanation:

4 x 3 = 12

Work check:

Trashcan : 3 feet

Lamppost: x4 bigger

3 + 3 + 3 + 3 = 12

4 + 4 + 4 = 12

Therefore, the lamp post is 12 feet tall (144 inches.)

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6