PROPERTIES OF TANGENTS

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PROPERTIES OF TANGENTS
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TANGENT a LINE that intersects the circle
exactly ONE time
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Common Tangents
http//www.ies.co.jp/math/java/geo/comtan/comtan.h
tml
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YOUR TURN
3 common tangents
0 common tangents
1 common tangent
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Point of Tangency
If a line is tangent to a circle, then it is
perpendicular to the radius drawn to the point of
tangency
More Pythagorean Theorem type problems! Yeah!! ?
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1. Find x
leg2 leg2 hyp2
92 122 x2
x 15
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2. Find RQ
leg2 leg2 hyp2
122 (QR)2 (812)2
122 (QR)2 202
RQ 16
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YOUR TURN!!! Find PT
leg2 leg2 hyp2
r2 482 (r36)2
P
r2 2304 r2 72r1296
r
r
r14
36
T
48
U
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R
S
If two segments from the same exterior point are
tangent to a circle, then they are congruent.
T
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3. Find x
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4. Find x
A
C
B
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YOUR TURN Find x
A
C
B
13
Homework Practice!!! page 186 (12-22 evens)