Circles: Tangents, Chords, Arcs, & Inscribed Angles

Front

What is a tangent to a circle?

Back

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

Front

Define a chord in a circle.

Back

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

Front

What is the relationship between central angles and arcs in a circle?

Back

Congruent central angles subtend congruent arcs.

Front

How do you find the length of a chord given the radius and the angle subtended at the center?

Back

Use the formula: Length of chord = 2 * r * sin(θ/2), where r is the radius and θ is the angle in degrees.

Front

What is an inscribed angle?

Back

An inscribed angle is formed by two chords in a circle which share an endpoint.

Front

State the Inscribed Angle Theorem.

Back

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

Front

How do you calculate the perimeter of a polygon inscribed in a circle?

Back

Add the lengths of all the sides of the polygon.

Front

What is the relationship between the angles formed by two tangents drawn from a point outside the circle?

Back

The angle formed is equal to half the difference of the intercepted arcs.

Front

If two chords intersect inside a circle, how do you find the lengths of the segments?

Back

The products of the lengths of the segments of each chord are equal.

Front

What is the formula for the area of a sector of a circle?

Back

Area of sector = (θ/360) * π * r², where θ is the angle in degrees and r is the radius.