Circle Geometry Concepts and Definitions

This video tutorial introduces geometry students to the basic vocabulary and concepts related to circles. It covers definitions and examples of key terms such as circle, radius, chord, diameter, secant, tangent, central angle, inscribed angle, arc, minor arc, major arc, and semicircle. The tutorial also explains formulas for calculating area, circumference, and arc length, providing a comprehensive overview of circle-related geometry.

What is the definition of a circle?

• A shape with four equal sides.

• A set of points at varying distances from a given point.

• A set of points equidistant from a given point.

• A line segment with one endpoint at the center.

How do we typically name a circle?

• By its circumference.

• By its diameter.

• By its center point.

• By its radius.

What is a radius?

• A segment with both endpoints on the circle.

• A line that intersects the circle in two places.

• A line that touches the circle at exactly one point.

• A segment with one endpoint at the center and one on the circle.

What is a chord?

• A line that touches the circle at exactly one point.

• A segment with one endpoint at the center and one on the circle.

• A line that intersects the circle in two places.

• A segment with both endpoints on the circle.

What makes a diameter different from a chord?

• It touches the circle at exactly one point.

• It is a line, not a segment.

• It has only one endpoint on the circle.

• It passes through the center of the circle.

What is a secant?

• A segment with both endpoints on the circle.

• A line that intersects the circle in two places.

• A line that touches the circle at exactly one point.

• A segment with one endpoint at the center and one on the circle.

What is a tangent?

• A line that intersects the circle in two places.

• A segment with both endpoints on the circle.

• A segment with one endpoint at the center and one on the circle.

• A line that touches the circle at exactly one point.

What is a central angle?

• An angle with the vertex on the circle.

• An angle with the vertex at the center and two sides that are radii.

• An angle with both sides as chords.

• An angle with one side as a tangent.

What is an inscribed angle?

• An angle with one side as a tangent.

• An angle with the vertex at the center.

• An angle with both sides as radii.

• An angle with the vertex on the circle and two sides that are chords.

What is a minor arc?

• An arc with a measure greater than 180 degrees.

• An arc with a measure equal to the circumference.

• An arc with a measure less than 180 degrees.

• An arc with a measure equal to 180 degrees.