Question: how many square inches is a 12 inch circle?
Answer: So if the radius of the circle is 12", then the area "A" is (approximately) 3.14 * 12^2 or about 3.14 * 144 = 452.16 square inches. If the diameter of the circle is 12", then the radius is 6" (half the diameter), and the area "A" is (approximately) 3.14 * 6^2 or about 113.04 sq.