Final answer:
To cover the inside of the race track, you will need 82,500 square feet of grass. This can be calculated by finding the area of the rectangular center and two semi-circles on each end.
Step-by-step explanation:
To find the amount of grass needed to cover the inside of the race track, we need to calculate the area of the rectangular center and the two semi-circles on each end.
- First, find the area of the rectangular center by multiplying its length (100 feet) by its width (40 feet): Area = 100 feet * 40 feet = 4000 square feet.
- Next, find the area of a semi-circle by dividing its circumference by 2 and multiplying it by the radius squared. Since we know the length of the rectangle is the diameter of the semi-circle, the radius is half of that, which is 50 feet: Radius = 50 feet. The circumference of a circle can be found by multiplying its diameter by pi (approximately 3.14): Circumference = 100 feet * 3.14 = 314 feet. Therefore, the area of a semi-circle is Area = (314 feet / 2) * (50 feet * 50 feet) = 39250 square feet.
- Since there are two semi-circles, we need to multiply the area by 2: Total Area of the Semi-circles = 39250 square feet * 2 = 78500 square feet.
- Finally, add the area of the rectangular center and the total area of the semi-circles to find the total amount of grass needed: Total Grass Needed = 4000 square feet + 78500 square feet = 82500 square feet.