Circle Vocabulary

A circle is defined as the set of all points that are equidistant from the center, forming a round shape. Therefore, options 1, 2, and 3 are not correct descriptions of a circle.

The correct definition of the radius is the length of a straight line from the center of a circle to its edge. It is not the distance around a circle, the measurement across a circle through the center, or the angle formed by two radii in a circle.

In geometry, a chord is a segment whose endpoints are on the circle, distinguishing it from a radius which connects the center of the circle to any point on the circle, and a secant which connects any two points on the circle. A line segment connecting the center of the circle to a point outside the circle does not qualify as a chord.

The diameter of a circle is a line segment that passes through the center of the circle and whose endpoints lie on the circle. It is double the length of the radius of the circle.

An arc is a portion of the circumference of a circle. It is a curved line connecting two points on a circle.

A semicircle is a two-dimensional shape that is exactly half of a circle, with a perimeter of half the circumference of the full circle.

A major arc is defined as an arc whose measure is greater than 180 degrees, which means it covers more than half of the circle. This is in contrast to minor arcs, which have measures less than or equal to 180 degrees.

A Minor Arc is defined as an arc on a circle whose measure is less than 180 degrees. It is important to understand the distinctions between different types of arcs in geometry.

A central angle is defined by its vertex at the center of the circle.

An intercepted arc is defined as an arc that is formed by an angle intersecting the circle, not necessarily connecting two points or going through the center of the circle. The correct answer describes the nature of an intercepted arc accurately.

A tangent is a line that touches a circle at exactly one point without crossing through the circle. This point of intersection is known as the point of tangency.

A secant is a line that intersects a circle at two points, creating a chord within the circle.

An inscribed angle is formed by two chords in a circle that intersect inside the circle, and the vertex of the angle is on the circle itself. This property distinguishes it from other types of angles in circle geometry.

An interior angle is defined as an angle formed by two intersecting lines with a vertex inside the circle, not on the circumference or outside the circle.

An exterior angle is formed by extending one side of a polygon beyond the vertex, not necessarily related to circles or angles greater than 90 degrees.

A sector is a portion of a circle that resembles a slice of pie, hence the comparison.