CIRCUMFERENCE+AREA OF A CIRCLE

The area (A) of a circle is given by the formula: A = $$\frac{1}{4} \times \text{π} \times d^2$$ or A = $$\text{π} \times r^2$$ , where d is the diameter and r is the radius.

The circumference (C) of a circle is given by the formula: C = $$\text{π} \times d$$ or C = $$2 \times \text{π} \times r$$ , where d is the diameter and r is the radius.

The diameter is the distance across the circle, passing through the center. It is twice the length of the radius.

The radius is the distance from the center of the circle to any point on its circumference.

Using the formula A = $$\text{π} \times r^2$$ , the area is A = $$3.14 \times 10^2 = 314 \text{ in}^2$$ .

Using the formula C = $$\text{π} \times d$$ , the circumference is C = $$3.14 \times 20 = 62.8 \text{ in}$$ .

The value of π (pi) is approximately 3.14, but it is an irrational number and its decimal representation goes on infinitely.

To convert diameter to radius, divide the diameter by 2: $$r = \frac{d}{2}$$ .

Using the formula C = $$2 \times \text{π} \times r$$ , the circumference is C = $$2 \times 3.14 \times 5 = 31.4 \text{ in}$$ .

Using the formula A = $$\text{π} \times r^2$$ , first find the radius: r = 6 inches. Then, A = $$3.14 \times 6^2 = 113.04 \text{ in}^2$$ .