1) The shape of the sidewalk is an ring with exterior radius equal to the radious of the fountain + 5 feet and inner radius equal to the radius of the fountain.
2) The area of such ring is equal to the area of the outer circle less the area of the inner circle (the fountain)
Area of a circle = π × r²
Area of the outer circle: π (10ft + 5 ft)² = π (15 ft)² = 225 π ft²
Area of the inner circle = π (10ft)² = 100 π ft²
Area of the ring (sidewald) = 225π ft² - 100π ft² = 125π ft² = 392.699 ft²
The garden at the Skyview office park has a water fountain at the center. The sidewalk aroung the fountain is 10 feet, what is the area of the sidewalk?
Solution: Area of the Sidewalk = Area of the outer circle - Area of the inner Consider the area of a circle: Area of a circle = π × r²
Area of the outer Circle= π × (10+5)² Area of the outer Circle= 706.86 square feet
Area of the inner circle= π × (10)² Area of the inner circle= 314.16 square feet
Area of the Sidewalk = Area of the outer circle - Area of the inner Area of the Sidewalk = 706.86 square feet - 314.16 square feet Area of the Sidewalk = 392.7 square feet
The table at the right shows how much tony earns per hour for his summer jobs one day tony spends 3 hours running errands he wants to use the money from his job to buy two banners.
