Use the formula: Area = πr²
Find the radius by dividing the diameter by 2: r = d/2
Substitute into the formula: Area = π(d/2)²
Simplify the formula: Area = πd²/4
Multiply π by the diameter squared, then divide by 4
Use π ≈ 3.14159 if needed
Use the formula: Area = πr²
Find the radius by dividing the diameter by 2: r = d/2
Substitute into the formula: Area = π(d/2)²
Simplify the formula: Area = πd²/4
Multiply π by the diameter squared, then divide by 4
Use π ≈ 3.14159 if needed