FA 3.1 Parts of a circle

A chord is a line segment with both endpoints on the circle.

The diameter is a chord that passes through the center of the circle and is the longest chord.

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

The radius is half the diameter. If the diameter is $$d$$ , then the radius $$r = \frac{d}{2}$$ .

The center is the point that is equidistant from all points on the circle.

An arc is a part of the circumference of a circle.

The circumference is the distance around the circle, calculated as $$C = \text{diameter} \times \text{π}$$ .

The area of a circle is calculated using the formula $$A = \text{π} \times r^2$$ , where $$r$$ is the radius.

The radius is 5 m.

A central angle is an angle whose vertex is at the center of the circle and whose sides are radii.