Download Angles Formed by Intersecting Lines

Section 14.1:
Angles Formed by Intersecting Lines
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Objective:
By following instructions, students will be able to:
1. Find the measures of angles formed by intersecting
lines.
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DEF: complementary angles – two angles whose sum of
their measures is 90 degrees.
DEF: supplementary angles – two angles whose sum of
their measures is 180 degrees.
COMPLEMENTARY ANGLES
(adjacent and nonadjacent)
SUPPLEMENTARY ANGLES
(adjacent and nonadjacent)
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Def: linear pair – two adjacent angles whose non
common sides are opposite rays.
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Def: vertical angles– two angles whose sides form
two pairs of opposite rays.
• Angles are congruent
120
60
60
120
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explain 1
Cross braces help keep the deck posts straight. Find the measure of
each angle.
a)
6
b)
5 and7
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Your-Turn #1
The measures of two vertical angles are given by the
expressions (x + 3)° and (2x - 7)°. Find the value
of x. What is the measure of each angle?
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DEF: complementary angles – two angles whose sum of
their measures is 90 degrees.
DEF: supplementary angles – two angles whose sum of
their measures is 180 degrees.
COMPLEMENTARY ANGLES
(adjacent and nonadjacent)
SUPPLEMENTARY ANGLES
(adjacent and nonadjacent)
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explain 2
Use the diagram below to find the missing angle measures. Explain
your reasoning.
a) Find the measures of
AFC and AFB.
b) Find the measures of
DFE and AFE.
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Revisit Objective:
Did we…
1. Find the measures of angles formed by intersecting
lines?
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HW:
Sec 14.1 pg 508 #s 1-12
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