Altitudes and Perpendicular Bisectors

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Altitudes and Perpendicular Bisectors
What You'll Learn
You will learn to identify and construct _______
and__________________ in triangles.
altitudes
perpendicular bisectors
altitude
perpendicular bisector
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Altitudes and Perpendicular Bisectors
In geometry, an altitude of a triangle is a
____________ segment with one endpoint at a
______ and the other endpoint on the side _______
that vertex.
perpendicular
vertex
opposite
D
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Altitudes and Perpendicular Bisectors
Drawing an altitude of a triangle
1) Draw a triangle like ?ABC
B
2) Use your protractor to draw a perpendicular
segment from B to side AC
A
C
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Altitude

• How many altitudes does every triangle have?

vertex
altitude
Question What happens when you cant draw a
perpendicular line from the vertex to the
opposite side shown?
opposite side
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Altitudes and Perpendicular Bisectors
An altitude of a triangle may not always lie
inside the triangle.
acute triangle
right triangle
obtuse triangle
The altitude is _____ the triangle
The altitude is _______ the triangle
The altitude is _____ of the triangle
inside
a side
out side
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Altitudes and Perpendicular Bisectors
Do the Your Turn problems on page 235
Answers no, yes, yes
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Altitudes and Perpendicular Bisectors
Another special line in a triangle is a
perpendicular bisector.
A perpendicular line or segment that bisects a
____ of a triangle is called the perpendicular
bisector of that side.
side
A
B
C
D
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Altitudes and Perpendicular Bisectors
In some triangles, the perpendicular bisector and
the altitude are the same.
Y
Z
X
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Altitudes and Perpendicular Bisectors
Do the Your Turn problems on page 236
Answers no, no, yes
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Altitudes and Perpendicular Bisectors
Assignment
Page 237/ 4-18, 22-28