Circles tangents, secants, chords, and angles

Front

What is a tangent to a circle?

Back

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

Front

What is a secant line?

Back

A secant line is a line that intersects a circle at two points.

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 the angles formed by a tangent and a chord?

Back

The angle formed between a tangent and a chord through the point of contact is equal to the angle in the alternate segment.

Tags

CCSS.HSG.C.A.2

Front

How do you find the radius of a circle if you know the diameter?

Back

The radius is half of the diameter.

Tags

CCSS.7.G.B.4

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2πr, where r is the radius.

Tags

CCSS.7.G.B.4

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius.

Tags

CCSS.7.G.B.4

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 a point outside the circle to the points of tangency are equal.

Tags

CCSS.HSG.C.A.2

Front

What is the angle subtended by a chord at the center of the circle?

Back

The angle subtended by a chord at the center is twice the angle subtended at any point on the circumference.

Tags

CCSS.HSG.C.A.2

Front

How do you calculate the angle between two intersecting chords?

Back

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

Tags

CCSS.HSG.C.A.2