Parts of a circle

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

What is 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 a diameter?

Back

The diameter is a line segment that passes through the center of the circle and has its endpoints on the circle. It is twice the length of the radius.

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 are radii of the circle.

Front

What is an inscribed angle?

Back

An inscribed angle is an angle formed by two chords in a circle which have a common endpoint. The vertex of the angle is on the circle.

Front

How do you calculate the circumference of a circle?

Back

The circumference can be calculated using the formula C = 2πr, where r is the radius.

Front

What is the relationship between the central angle and the inscribed angle?

Back

The inscribed angle is half the measure of the central angle that subtends the same arc.

Front

What is a sector of a circle?

Back

A sector is a region of a circle bounded by two radii and the arc between them.

Front

What is a chord in a circle?

Back

A chord is a line segment whose endpoints lie on the circle.

Front

What is the arc length of a circle?

Back

The arc length is the distance along the curved line of a circle between two points on the circle.