Download Classifying Triangles Using Pythagorean Theorem

Classifying Triangles Using
Pythagorean Theorem
Samantha Louis
Intro.
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You can classify a triangle by their angle
measures using the Pythagorean Theorem.
The Pythagorean Theorem can help classify
a triangle as obtuse, acute, or right.
C² = A² + B² is the Pythagorean Theorem
formula.
Formula.
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C² = A² + B²
To use this formula, plug in the length of the 2
legs of the triangle into A and B and the
hypotenuse into C.
If C² is greater than (>) A² + B² than the
triangle is classified as obtuse.
If C² is less than (<) A² + B² than the triangle
is classified acute.
If C² is equal to (=) A²+ B² than the triangle is
classified as right.
Example.
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C² = A² + B²
15² = 9² + 13²
225 = 81 + 169
225 < 250
The triangle is
classified as acute
because 225 is less
than 250.
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Example.
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C² = A² + B²
12² = 9² + 4²
144 = 81 + 16
144 > 97
The triangle is
classified as obtuse
because 144 is
greater than 97.
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Example.
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C² = A² + B²
10² = 8² + 6²
100 = 100
The triangle is
classified as right
because 100 equal
to 100.
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Helpful Websites
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http://www.education.com/reference/article/cl
assifying-triangles/
http://www.cliffsnotes.com/study_guide/Exten
sion-to-the-PythagoreanTheorem.topicArticleId-18851,articleId18820.html
http://www.tutorvista.com/bow/classifytriangles-learning
Converse Consecutive Angle
Theorem
Definition: Two angles that are on opposite
sides of the transversal outside of
the lines it intersects. If the 2 two
lines are parallel these angles are
supplementary. This theorem
stems from corresponding angle
postulate.
Rules, Properties and Formulas
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If consecutive angles are
supplementary then the lines are
parallel
Examples
Name all consecutive
angle pairs
Sites:
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http://www.waterfordmgmt.com/school/Prepar
ed_Notes/parallel_line_geometry.pdf
http://quizlet.com/726842/geometry-chapter3-vocab-thanks-to-katie-flash-cards
http://www.cliffsnotes.com/study_guide/Testin
g-for-Parallel-Lines.topicArticleId18851,articleId-18780.html
Triangle Classification by
Sides and Angles
Summary
Lili Feinberg
This goal of this slideshow is to show you all of the
possible ways to classify triangles by their sides or angles.
You can classify a triangle by its sides by calling it an
isosceles triangle, a scalene triangle, or an equilateral
triangle. You can classify a triangle by its angles by calling
it an equiangular triangle, a right triangle, an acute triangle,
or an obtuse triangle. The angle classification always goes
before the side classification.
Rules
Equilateral Triangle: A triangle with all three sides equal in
measure.
Isosceles Triangle: A triangle in which at least two sides have
equal measure.
Scalene Triangle: A triangle where all three sides are different
Measures.
Right Triangle: A triangle that has a right angle in its interior.
Acute Triangle: A triangle with all acute angles in its interior
(less than 90 degrees).
Obtuse Triangle: A triangle with an obtuse angle in its interior
(less than 180 degrees, but more than 90 degrees).
Equiangular Triangle: A triangle having all angles of equal
Measure.
Examples
Classify the triangles by their sides and angles.
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Click the space bar to reveal the answers so you can check them.
Equiangular Equilateral
Right Isosceles
Acute Scalene
Converse Corresponding
Angles Postulate
By Katie Ostuni
Definition
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The Converse Corresponding Angle Postulate is if
two lines are cut by a transversal so that
corresponding angles are congruent, then two lines
are parallel.
Rules, Properties, and important
information.
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The converse corresponding angles postulate says that if
two lines are cut by a transversal so that corresponding
angles are congruent then two lines are parallel.
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A converse is a situation, object or statement that is the
reverse of another.
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The Converse came from the corresponding angles
postulate which says if two parallel lines are cut by a
transversal then corresponding angles are congruent.
Examples
Are these lines parallel ?
Answer: yes they are because of the converse
corresponding angles postulate.
Examples (Cont.)
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Is this an example of the Converse
Corresponding Angles Postulate?
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Answer: no, this is an example of the
converse alternate interior angles postulate.
Web Pages
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http://hotmath.com/hotmath_help/topics/
corresponding-angles-postulate.html
http://www.regentsprep.org/regents/mat
h/geometry/GPB/theorems.htm
http://www.regentsprep.org/regents/mat
h/geometry/GPB/theorems.htm