MEDIANS, ALTITUDES

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LESSON 5-3 MEDIANS, ALTITUDES ANGLE BISECTORS
OF TRIANGLES
OBJECTIVE To define and use medians, altitudes
and angle bisectors of triangles
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DEFINITIONS
A median of a triangle
is a segment whose endpoints are a vertex of the
triangle and the midpoint of the opposite side.
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 EX. 1 Sketch, label and mark 3 medians for
?ABC.
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An altitude of a triangle
is a segment from a vertex of the triangle and
perpendicular to the line containing the
opposite side.
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EX. 2  Sketch, label mark altitudes for each
of the 3 triangles.
T
U
V
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An angle bisector in a triangle
is a segment that bisects one of the angles of a
triangle and whose endpoints are on the triangle.
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C
EX. 3  Sketch, label and mark angle bisectors
for ?CAR.
A
R
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STATEMENTS REASONS
1. BD is a med of ?ABC 1. GIVEN
2. Def. of med.
3. Def. of midp.
4. GIVEN
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5. Ref. Prop ?
6. SSS Post.
6. ?ABD ? ?CBD
7. CPCTC
7. ?ABD ? ?CBD
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ASSIGNMENT
Lesson 5.3 Worksheet