Geometry - Circles 15.1, 15.2, & 15.3

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 diameter of a circle?

Back

The diameter is a straight line passing from side to side through the center of a circle, measuring twice the radius.

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 central angle?

Back

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

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.

Front

What is a circumscribed angle?

Back

A circumscribed angle is an angle formed outside a circle by two tangents or a tangent and a secant.

Front

What is the relationship between the inscribed angle and the arc it intercepts?

Back

The inscribed angle is half the measure of the intercepted arc.

Front

What is the formula for the circumference of a circle?

Back

The circumference C of a circle is given by the formula C = 2πr, where r is the radius.

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

What is a chord in a circle?

Back

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