Lines and Centers of Circles

The line segment between the center and a point on the circle is called its:

• Radius

• Diameter

• Chord

• Tangent

A line segment between two points on the circle which passes through the center is called a:

• Radius

• Diameter

• Chord

• Tangent

What is the radius of this circle?

• 18

• 72

• 38

• 14

What is the diameter of this circle?

• 8

• 16

• 10

• 4

When a central angle, inscribed angle or any two lines (or segments) intersect a circle's circumference, the type of arc created is called a(n)

• inscribed arc

• central arc

• intercepted arc

• isoceles arc

radius

• a line segment connecting two points on a circle

• a line segment connecting two circles

• a line segment that goes from one point on a circle to another point through the center of the circle

• a line segment from a circles center to a point on the circle

A tangent line XY touches the circle A at point B and formed the radius AB. Is it true that the radius AB perpendicular to the tangent line XY?

• Yes, the radius is perpendicular to the tangent line.

• Yes, the tangent line is the radius of the circle.

• No, the radius is not perpendicular to the tangent line.

• No, the radius of the circle is secant and tangent to the circle.

In the figure shown, line m and line n are common external tangents to circles A and B. If line m = 2x + 7 and line n = 3x – 8, how long are lines m and n?

• 37

• 45

• 15

• 30

Segment AB is a common external tangent to circles P and Q with measurement of x. The radius AP of circle P measures 18 units long and the radius QB of circle Q measures 8 units longs. The line segment between the centers of the circles measure 26 units long. Find x.

How many common tangents are drawn in the figure?

• 1

• 2

• 3

• 4