Geometry Unit 9 - Circles Test (Part I - Mult Choice) HONORS

In the diagram, central angle AOC measures 80 degrees. What is the number of degrees in the measure of inscribed angle ABC?

• 80

• 20

• 160

• 40

In the diagram, CD is tangent to circle O at B. If  $m\angle AOB$  = 130, find  $m\angle ABD$ . 

• 130

• 25

• 230

• 65

In the diagram with parallel chords, find the measure of the arc marked with an x.

• 40

• 80

• 120

• 240

In the diagram, AB, BC and AC are tangents to circle O at points F, E, and D, respectively, AF = 6, CD = 5, and BE = 4.

What is the perimeter of  $\Delta ABC$ ? 

• 15

• 25

• 60

• 30

In the diagram of circle O, PA is tangent to circle O at A, and PBC is a secant with points B and C on the circle.

If PA = 8 and PB = 4, what is the length of PC?

• 16

• 20

• 15

• 12

Secants JKL and JMN are drawn to circle O from an external point, J. If JK = 8, LK = 4, and JM = 6, what is the length of JN?

(Diagram not drawn to scale.)

• 16

• 12

• 10

• 8

In the diagram of circle O, chords AD and BC intersect at E, m arcAC = 87, and m arcBD = 35.

What is the degree measure of $\angle CEA$ ? 

• 87

• 61

• 43.5

• 26

In the diagram of circle O, chord AB is parallel to chord CD.

A correct justification for m arcAC = m arcBD in circle O is

• parallel chords intercept congruent arcs

• congruent chords intercept congruent arcs

• if two chords are parallel, then they are congruent

• if two chords are equidistant from the center, then the arcs they intercept are congruent

The angle formed by the radius of a circle and a tangent to that circle has a measure of

• $45^o$

• $90^o$

• $135^o$

• $180^o$

In the diagram, AC and AD are tangent to circle B at points C and D, respectively, and BC, BD, and BA are drawn.

If AC = 12 and AB = 15, what is the length of BD?

• 5.5

• 9

• 12

• 18