Answer:
shaded area ≈ 69.53 cm²
Explanation:
the shaded area (A) is calculated as
A = area of square - area of circle
area of square = 18² = 324
area of circle = πr² ( r is the radius )
the diameter of the circle = 18 , so r = 18 ÷ 2 = 9
area of circle = π × 9² = 81π
then
A = 324 - 81π ≈ 69.53 cm² ( to 2 decimal places )