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

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Lesson Plan #33
Date: Wednesday November 21st, 2012
Class: Geometry
Topic: Proving triangles congruent by 𝑎. 𝑎. 𝑠. ≅ 𝑎. 𝑎. 𝑠.
HW #33:
Aim: How do we prove triangles congruent by 𝑎. 𝑎. 𝑠. ≅ 𝑎. 𝑎. 𝑠.?
Objectives:
Students will be to prove triangles congruent by 𝑎. 𝑎. 𝑠. ≅ 𝑎. 𝑎. 𝑠.
Do Now:
1)
PROCEDURE:
Write the Aim and Do Now
Get students working!
Take attendance
Give Back HW
Collect HW
Go over the Do Now
Assignment #1: Complete the proof below
Statements
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5)
<𝐵 ≅<𝐸
< 𝐶 ≅< 𝐹
̅̅̅̅
𝑨𝑪 ≅ ̅̅̅̅
𝑫𝑭
<𝐴 ≅<𝐷
𝚫𝑨𝑩𝑪 ≅ 𝚫𝑫𝑬𝑭
Reasons
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2)
3)
4)
5)
Theorem: Two triangles are congruent if two angles and a side opposite one of the angles in on triangle are congruent to the
corresponding two angles and side of the other [𝑎. 𝑎. 𝑠. ≅ 𝑎. 𝑎. 𝑠. ]
Online Interactive Activity: Let’s see AAS in action
http://www.mathopenref.com/congruentaas.html
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Does Angle Angle Angle work as a way to prove triangles congruent?
Online Interactive Activity : Let’s go to this URL and see if Angle Angle Angle works as a way to prove triangles
congruent
http://www.mathopenref.com/congruentaaa.html
Does Angle Side Side works as a way to prove triangles congruent?
Online Interactive Activity: Let’s go to the URL and see to see if Angle Side Side works as a way to prove triangles
congruent
http://www.mathopenref.com/congruentssa.html
Assignment #2:
Assignment #3:
Assignment #4:
Given:
̅̅̅̅
C is the midpoint of 𝐵𝐸
̅̅̅̅
𝐴𝐵 ∥ ̅̅̅̅
𝐷𝐸
Prove:
Δ𝐴𝐵𝐶 ≅ Δ𝐷𝐶𝐸
Statements
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2)
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7)
Reasons
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2)
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7)
Assignment #5:
Sample Test Questions:
1) Which of the following is not a postulate or theorem for congruence of triangles?
A) ASA
B) SAS
C) AAS
D) SSA
If enough time:
Do the HW questions