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 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 the radius of a circle?

Back

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

Front

What is the relationship between angles in an inscribed quadrilateral?

Back

In an inscribed quadrilateral, opposite angles are supplementary (they add up to 180°).

Front

What is the measure of an angle formed by a diameter and a chord?

Back

The angle formed by a diameter and a chord is a right angle (90°).

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 whose endpoints lie on the circle.

Front

What is a tangent to a circle?

Back

A tangent is a line that touches the circle at exactly one point.

Front

What is the central angle of a circle?

Back

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