WS 9-9-5 Circle Geometry – Unit Review - AbbyNet

WS 9-9-5 Circle Geometry – Unit Review
Name: ______________
1. Identify all tangents and chords for each circle.
a. b. c. d.
2. Each circle below has a centre at O and a point of tangency at T. Find the measure of the numbered
angles and state the property used.
a. b. c.
3. Each circle below has a centre at O and a point of tangency at T. Determine the value of x.
a. b. c.
4. Each circle below has a centre at O and a point of tangency at T. Determine the value of n.
a. b.
5. Each circle below has a centre at O. Determine the measure of the numbered angles and state the
properties used.
a. b. c.
Math Makes Sense 9 Pg 403 #1-2, 4, Pg 418 #1-2, 5, 7-8, 10bc, Pg 420 #1-2

WS 9-9-5 Circle Geometry – Unit Review
Name: ______________
Answers:
1.
2.
a. Chords: EF
Tangents: AC
b. Chords: CE
Tangents: AB
c. Chords: HE
Tangents: AC
d. Chords: BD
Tangents: FH, JH
a. ∠1 = 90°, Radius-Tangent Theorem
b. ∠1 = 90°, Radius-Tangent Theorem
∠2 = 20°, Angle sum of a triangle = 180
c. ∠1 = 5°, Radius-Tangent Theorem
and angle sum of a triangle = 180
3. Use Pythagoras!
a. x = 12.50 cm
b. x = 9.65 cm
c. x = 4.77 cm
4. Draw a radius from O to T then use Pythagoras!
a. n = 4.90 cm
b. n = 14.83 cm
5. Radii in a circle are equal!
a. AO=BO, radii in a circle are equal
∠1 = 30°, angles opposite equal sides are equal
b. XO = YO, radii in a circle are equal
∠1 = 65°, angles opposite equal sides are equal
∠2 = 50°, angle sum of a triangle = 180
c. MO=NO, radii in a circle are equal
∠1 = 100°, radii in a circle are equal,
angles opposite equal sides are equal,
and angle sum of a triangle = 180