Answer:
circle area = 1963.495 ft²
Explanation:
Given
A rectangle 550 ft by 350 ft packed with circles on a rectangular grid
Find
the area of the largest circle that can be packed this way
Solution
The diameter of the circle must be a factor of both 350 and 550. We want the diameter to be the largest such factor. We can write the factors of 350 and 550 as ...
- 350 = 50 × 7
- 550 = 50 × 11
The largest factor common to both numbers is 50, so that will be the diameter of the largest circle that will fit on a square grid.
The area of a circle is commonly given by the formula ...
A = πr² . . . . . where r represents the radius of the circle.
The radius is half the diameter, so will be (50 ft)/2 = 25 ft. And the area of the circle is ...
A = π(25 ft)² = 625π ft² ≈ 1963.495 ft²
The area of one circle is about 1963.495 square feet.
_____
The total number of circles is 11×7 = 77. Their total area is 77×1963.495 ft² ≈ 151,189 ft². This is 151,189/192,400 ≈ 78.54% of the total area of the rectangle.