Unit 6C

The center of a circle is the point that is equidistant from all points on the circle's circumference.

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

The diameter of a circle is twice the length of the radius and is the longest distance across the circle.

The area of a circle is calculated using the formula A = πr², where r is the radius.

The value of π (pi) is approximately 3.14.

A sector of a circle is a portion of the circle enclosed by two radii and the arc between them.

The area of a sector can be found using the formula A = (θ/360) × πr², where θ is the angle in degrees.

The diameter is twice the radius (d = 2r).

The circumference of a circle is the distance around it, calculated using the formula C = 2πr.

To convert diameter to radius, divide the diameter by 2 (r = d/2).