Download Geometry Fall 2014 Lesson 026 _Using more than one pair of

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Lesson Plan #26
Date: Monday October 28th, 2013
Class: Geometry
Topic: Using two pairs of congruent triangles
Aim: How do we use two pairs of congruent triangles?
HW #26:
Note: Postulate – If a, b, and c are real numbers, such that a > b, and b > c, then a > c
Also known as the transitive property of inequality
Objectives:
1) Students will be able to use two pairs of triangles congruent.
Do Now:
Write a plan for how you would prove the
PROCEDURE:
Write the Aim and Do Now
Get students working!
Take attendance
Give Back HW
Collect HW
Go over the Do Now
Statements
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Reasons
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On your own:
Definition: An exterior angle of a polygon is an angle that forms a linear pair with one the interior angles of the polygon.
For each exterior angle, the interior angle that it
forms a linear pair with is called an adjacent interior
angle. The remaining two angles are called the
remote interior angles.
Online Activity: http://www.mathopenref.com/trianglesideangle.html
Theorems presented without proof:
Theorem: An exterior angle of a triangle is greater than the any of the two remote interior angles or An exterior angle of a triangle
is always larger than either opposite interior angle.
http://www.mathopenref.com/triangleextangletheorem.html
Proof in blue book page 194.
Theorem: If the lengths of two sides of a triangle are unequal, the measures of the angles opposite those sides are unequal and the
greater angle lies opposite the greater side.
Theorem: If the measures of two angles of a triangle are unequal, the lengths of the sides opposite these angles are unequal and
the greater side lies opposite the greater angle.
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Fix the diagram for ex 3 and ex 4
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Regents Exam Questions:
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