First you need to find the radius of the circle because the formula for the area is π × radius². To find the radius, you divide 28.26 by 3.14 to find the diameter, which is 9, and then divide that by 2 to get 4.5. Now you can substitute the radius into the expression and get 3.14 × 4.5² = 63.6 cm². I hope this helps!