Download Triangle Congruence - Ms. Huls` Math Class

Happy Friday Eve
Please do the following:
• Find new seat on whiteboard
• Pick up the papers from the front table.
• Take out Classwork from last period
• Goal Posters
WARM-UP
Homework:
HW #1: Finish classwork #1
HW #2: Worksheet
Agenda
1. Group Posters
2. Intro to Congruent Triangles
Office Hours!
Everyday at lunch
Thursday= FLEX ( leaving at 3:15).
Saturday School ( 9am-1pm)
Learning Objective(s)
By the end of this period you will be able to:
① Use properties of congruent triangles
② Apply SSS and SAS to construct triangles and to solve problems
Goal Posters
Take them out and Paper Passer will collect it
Group Norms/Posters
You are going to create posters for your group.
Look at the template provided.
Before we do this, let’s look at values that we
created from last semester
Feedback
Either go to my website and find the link OR
Type this in to your phone.
http://bit.ly/2llLOAo
This is anonymous so be AS HONEST AS POSSIBLE!
When done, take a screenshot that you completed it or
you can email it to me: [email protected]
Warm-Up
Let’s Review Warm-Up
Open Notebook
Title Notes: Congruent Triangles
Congruent Triangles
Congruent Triangles
– If two figures have the same shape and the same size,
they are congruent
Congruence Statements
• ORDER MATTERS based on congruent parts
Ex 1: Congruent Triangles
Congruence Statement:
Corresponding Congruent Angles:
Corresponding Congruent Sides:
Congruent Triangles
Conditions for Congruent Triangles
Two figures are congruent if they meet both
conditions:
①Corresponding angles are congruent
②Corresponding side lengths have a common
ratio of 1.
Symbol for congruence
Math Joke of the Day
• What do you call a fierce beast?
• A line
HW #1:
Use this time wisely 
When done, raise your hand and I will stamp it
off.
I am going to give you until ________ to finish
it!
Whiteboards
Grab a whiteboard!
Quick Check!
Name the included angle in each triangle.
G
I
H
Quick Check
1. If triangles are similar, what is true about
corresponding sides and angles?
1. If triangles are congruent, what is true about
corresponding sides and angles?
2. What is the difference between similarity and
congruence?
Triangle Congruence
Instead of having to prove that all sides and angles are congruent in
order to prove that triangles are congruent, we are going to learn 5
shortcuts.
There are five ways to prove triangles are congruent:
1. SSS
2. SAS
3. ASA
4. AAS
5. HL
Notes
Triangle Congruence Conjectures
Fill in the blanks as we go along. I will give you time to glue the paper
into your composition notebook.
We will go over Examples and Non-Examples. You may want to draw
more down in your notebook!
SSS and SAS
Side–Side–Side Congruence (SSS)
• If all three pairs of corresponding sides have equal length,
then ≅
What is a possible congruent statement for the figures?
• Examples
• Non-Examples
Side-Angle-Side Congruence
Side–Angle–Side Congruence (SAS)
• If two pairs of corresponding sides have equal length and
the angle in between them are equal, then ≅.
What is the possible congruence statement for the figures?
Example/ Non-Examples
• Example
• Non-Example
Math Joke of the Day
• What do you call a broken angle?
• A rectangle!
4-4 Triangle Congruence: SSS and
SAS
Angle–Side–Angle Congruence (ASA)
• If two angles and the side between them are congruent to
the corresponding angles and the side, then ≅
• What is a possible congruent statement for the figures?
ASA
• Examples
• Non-Examples
Angle-Angle-Side Congruence
Angle-Angle-Side(AAS)
• If two pairs of corresponding angles and a pair of
corresponding sides that are not between the angles have
equal measures, then ≅
What is the possible congruence statement for the figures?
Example/ Non-Examples: AAS
• Example
• Non-Example
Whiteboard!
On your whiteboard, draw a right triangle
1. Label the legs of the triangle
2. Label the hypotenuse
Hypotenuse-Leg (HL) Congruence
Hypotenuse-Leg Congruence (HL)
• If the hypotenuse and a leg of a right triangle are congruent
to the hypotenuse and a leg of another right triangle, then
the triangles are congruent.
• IMPORTANT: The hypotenuse is ALWAYS across from the
right angle ( highlight this in your notes)
Examples/Non-Examples: HL
• Example
• Non-Example
Whiteboards
Identify the postulate or theorem that proves the triangles
congruent.
HL
ASA
SAS or SSS
Whiteboard Flash!
I am going to show you two triangles
You are going to write down whether they are congruent by
SSS, SAS, AAS, ASA, or HL!
Once your entire table thinks they have it correct, STAND UP!
First table to have ALL their members stand up with the
correct statement wins that round.
Note: The triangles might not be congruent. If so, state they are not
congruent.
Flash Warm-Up!
I will show a picture and you will write on your
whiteboard what triangle congruence postulate
you should use to prove the triangles are
congruent.
Recall the possible postulates are:
1.
2.
3.
4.
SSS
SAS
ASA
AAS
(1)
(2)
Flash Do Now!
(2)
Flash Do Now!
(2)
Flash Do Now!
CHALLENGE: Flash Do Now!
(3)
Classwork #2
Homework #2