Three boards must be added.
Since the area of the table (
A = π × r²)
is 1,256 square inches, solve for r
²
by dividing 1,256 by 3.14. 1,256 square inches ÷
3.14 = 400 square inches
Then find the radius by
finding the square root of 400.
r =
= 20 inches
So, 20 inches is half the diameter of the table,
or half the length of each board. Each board is 40
inches long.
To find the total area of the additional boards,
subtract the original area of the circular table
from the increased area.
2,696 square inches − 1,256 square inches = 1,440
square inches
Find the area of each board by using the formula
A = l × w.
A = 40 × 12 = 480 square inches
Divide the total area provided by the additional
boards (1440) by the area of each board to get the
final answer. 1,440 square inches ÷ 480 square
inches = 3 boards