Question

A circular pond is to be surrounded by a gravel path. Use the diagram to find the square feet of gravel needed if we know the pond has a radius of 200 ft and the radius of the whole space is 250 ft?

Answer 1

Since no diagram is given, I'm guessing that it shows two concentric circles. The inner circle represents the pool while the annular space between the two circles represent the gravel path. So, in this problem, we have to determine the area of the annular space. We can determine this by subtracting the area of the smaller circle to the bigger circle. Knowing that the area of a circle is πr²,

Big circle = π(250/2)² = 49,087.4 ft²
Small circle = π(200/2)² = 31,415.93 ft²
Annular space = 49,087.4 ft² - 31,415.93 ft²
Annular space = 17,671.47 ft²

Therefore, the area covered by the gravel path is 17,671.47 ft².