1. Geom10.1­10.2.notebook March 01, 2012
BELL WORK: Chord AB measures A
12 mm and the radius of circle P is
10 mm.
Find the distance from AB to P.
P
B
(The distance from the center of a circle to the chord is the measure
of the perpendicular segment from the center of the chord.)
Theorems from yesterday's intro to circles:
• If a radius is perpendicular to a chord, then it bisects the chord.
• If a radius of a circle bisects a chord that is not a diameter, then it is
perpendicular to that chord.
• The perpendicular bisector of a chord passes through the center of the
circle.
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2. Geom10.1­10.2.notebook March 01, 2012
Homework questions? (p.443 #6,8,11,12,14)
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3. Geom10.1­10.2.notebook March 01, 2012
10.2 ­ Congruent Chords
We are going to talk about some relationships between chords.
Let's do it!
Theorem: If two chords of a circle are equidistant from the
center, then they are congruent.
Theorem: If two chords of a circle are congruent, then they are
equidistant from the center of the circle.
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4. Geom10.1­10.2.notebook March 01, 2012
C
Example:
B
Given: T, AB = CD
Q
T
OP = 12x ­ 5
P
OQ = 4x + 19
D
Find OP.
A
Find a partner near you, complete the following 2 problems as
your exit slip. I must check them and collect them before you
begin your homework:
1. In a circle, chord AB is 325 cm long and chord CD is 3 and
1/4 m long. Which is closer to the center of the circle?
B
Q
2. Given: P, PQ = PR
AB = 6x + 14 A
CD = 4 ­ 4x P
D
C R
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5. Geom10.1­10.2.notebook March 01, 2012
Homework: p.448 #6,11­13
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