Circle Basics, Central Angles, and Arcs.

Front

What is a circle?

Back

A circle is a set of points in a plane that are equidistant from a fixed point called the center.

Front

Define the radius of a circle.

Back

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

Front

What is the diameter of a circle?

Back

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

Front

What is a central angle?

Back

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

Front

How do you calculate the circumference of a circle?

Back

Circumference (C) can be calculated using the formula: C = 2πr, where r is the radius.

Front

What is an arc in a circle?

Back

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

Front

How do you find the length of an arc?

Back

The length of an arc can be found using the formula: Arc Length = (θ/360) * C, where θ is the central angle in degrees and C is the circumference.

Front

What is the formula for the area of a circle?

Back

The area (A) of a circle is given by the formula: A = πr², where r is the radius.

Front

Define a sector of a circle.

Back

A sector is a region enclosed by two radii and the arc between them.

Front

What is the relationship between the central angle and the arc length?

Back

The arc length is directly proportional to the central angle; as the angle increases, the arc length increases.