Circles: Tangents, Chords, and Inscribed Angles

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 a chord in a circle?

Back

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

Front

What is the relationship between a tangent and a radius at the point of tangency?

Back

The tangent is perpendicular to the radius at the point of tangency.

Front

What is an inscribed angle?

Back

An inscribed angle is formed by two chords in a circle which have a common endpoint.

Front

What is the measure of an inscribed angle in relation to the arc it intercepts?

Back

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

Front

If two tangents are drawn from a point outside the circle, what can be said about their lengths?

Back

The lengths of the two tangents from the external point to the circle are equal.

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2πr, where r is the radius.

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius.

Front

How do you find the radius if you know the diameter?

Back

Radius = Diameter / 2.

Front

What is the relationship between the angles formed by two intersecting chords?

Back

The measure of the angle formed is equal to half the sum of the measures of the arcs intercepted by the angle and its vertical angle.