Download Geometry Fall 2011 Lesson 17 (S.A.S. Postulate)

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Lesson Plan #20
Date: Friday October 17th, 2014
Class: Geometry
Topic: Proving triangles congruent by the S.S.S. postulate.
Aim: How do we prove triangles congruent by the S.S.S postulate?
HW #20:
Page 124 Written Exercises #’s 1-8
Objectives:
1) Students will be able prove triangles congruent using the S.S.S. postulate
Do Now:
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Statements
PROCEDURE:
Write the Aim and Do Now
Get students working!
Take attendance
Give Back HW
Collect HW
Go over the Do Now
Assignment: Copy the triangle shown
1) Construct a side congruent to
. Call it
.
2) Use your compass to measure
. Using that measurement put your compass point on D and draw a circle.
3) Use your compass to measure
. Using that measurement put your compass point on E and draw a circle.
4) Name the intersection of the circles F forming DEF.
5) With your protractor, measure angles A, B, and C and compare to angles D, E, F, respectively.
What do you notice?
If all six corresponding parts are congruent, what can we say about the two triangles?
Reasons
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http://www.mathopenref.com/congruentsss.html
Postulate: Two triangles are congruent if the three sides of one triangle are congruent respectively to the three sides of the
other triangle [s.s.s.s.s.s.]
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Sample Test Questions:
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