512b Triangles
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Transcript 512b Triangles
Triangles…
SOL5.12b
GES
Mrs. Norman
CLASSIFYING
TRIANGLES
CLASSIFYING TRIANGLES
Why do we classify triangles?
Artists and architects often use triangular elements in their designs.
Classifying triangles makes it easier to describe them.
CLASSIFYING TRIANGLES
How can these triangles be
classified?
One way is:
By the length of their sides.
4
4
4
5
7
5
9
2
8
CLASSIFYING TRIANGLES
Equilateral triangle
All sides are the same (equal) length.
The sum total of every triangle = 180°
So, if all of the angles are the same…
3 ÷ 180° = 60°
Each of the three angles of an
equilateral triangle is 60°
CLASSIFYING TRIANGLES
Isosceles triangle
At least two sides are the same (equal) length.
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4
6
4
4
CLASSIFYING TRIANGLES
Scalene triangle
No sides are the same (equal) length.
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2
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9
2
7
CLASSIFYING TRIANGLES
Another way you can classify
triangles is:
by the measure of their angles
CLASSIFYING TRIANGLES
Right triangle
One angle is a right (90°) angle.
The sides have special names.
The legs are the two sides that form a right triangle
The third side is the hypotenuse
hypotenuse
legs
legs
hypotenuse
CLASSIFYING TRIANGLES
Acute triangle
All three angles are acute angles.
CLASSIFYING TRIANGLES
Obtuse triangle
One angle is an obtuse angle.
CLASSIFY TRIANGLES
Isosceles:
Acute:
2 congruent sides
all angles are
acute
Scalene:
Obtuse:
each side a
different length
has an obtuse
angle
Equilateral:
all 3 sides
congruent
Right:
has a right
angle
Image from math.com
Now You know all
about Triangles…
So lets practice!
CLASSIFYING
TRIANGLES
BY SIDES AND ANGLES
http://www.ixl.com/math/grade-4/classify-triangles-by-side-lengths
http://www.ixl.com/math/grade-4/classify-triangles-by-angles
http://www.ixl.com/math/grade-7/classify-triangles
DIRECTIONS:
When the slide appears, say BOTH NAMES for the type of
triangle aloud before the computer shows you the answer.
Classify each triangle by both its SIDES and its ANGLES.
You will have 6 seconds.
Classify by sides:
Classify by angles:
Classify by sides:
also
Isosceles
Triangle
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Classify by sides:
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Classify by sides:
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Classify by sides:
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Classify by sides:
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Classify by sides:
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Classify by sides:
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Classify by sides:
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Classify by sides:
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Are you a
triangle
expert?