Chapter 12.4 Angle Measures and Segment Lengths

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Chapter 12.4 Angle Measures and Segment Lengths
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Vocabulary

• Secant a line that intersects a circles at two
  points.

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Theorem 12.11

• The measure of an angle formed by two lines that
• 1) Intersect inside a circle is half the sum of
  the measures of the intercepted arcs

y
x
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Theorem 12.11 Continue

• The measure of an angle formed by two lines that
• 2) Intersect outside a circle is half the
  difference of the measures of the intercepted arcs

y
x
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Example 1

• Find
• A)
• B)

46
90
20
95
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Theorem 12.12

• For a given point and circle, the product of the
  lengths of the two segments from the point to the
  circle is constant along any line through the
  point and circle

t
a
c
x
w
y
z
y
b
d
z
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Example 2
6
8
7
y
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Classwork/Homework

• Pgs 691-692 9-14, 20-25