Linear Algebra

Tuesday August 26

Homework answers

Homework Answers

Balancing a milk bottle

Answer is 3.44 miles per hour

Learning Target

Students will understand how much information is needed to decide if two triangles are congruent.

Connect to Prior Understanding

What do we remember about Problem 2.1We translated ABCD 2 cm to match C with PWe rotated ABCD counterclockwise to move to see if D matched with Q.We found that corresponding sides and angles were congruent.

2.2 Supporting the World

Video:http://dashweb.pearsoncmg.com/main.html?r=15512&p=402

Can you perform similar transformations to show whether any two triangles are congruent?Are any of the triangles congruent?How do you know?

Problem 2.2 A-F

Work with a group of 3-4 students to complete A-F.

Group Work Norms• Work on the investigation with your group of

four• Make sure everyone in your group participates• Answer all questions thoroughly• If you have a question raise your hand so that I

can can help you.

Problem 2.2In this problem you are going to focus on congruent triangles. Triangles are a very special family of geometric figures. They are used in many construction projects to provide strength and stability for structures.

You will need lab sheet 2.2 A-F

Discuss with your group how you can decide if triangles are congruent.

What tools could you use to help you determine if figures are congruent?

Questions

• Did you flip your tracing paper over? What line of symmetry are you thinking of?

• After you flip your tracing over this line do you need any other transformations?

• What did you do first in Question D?• Were all the triangles congruent?• How do you know they aren’t congruent?• Do the angles in Question E match?

Share answers

• Did other groups use different order for moving their figures?• Did you measure angles and sides before deciding if figures

were congruent?• How should you name the triangles to show the

corresponding congruent parts?• How did you know that the triangles Is in Question C are not

congruent?• How many sides do you have to measure to know that a pair

of triangles are not not congruent?• How do you know the triangles in Question E are not

congruent?

Rate your understanding

Students will understand that two figures are congruent if one can move one figure unto the other by a sequence of reflections, rotations and/or translations and will be able to show congruence by moving a copy of the original onto the figure.

Answers for problem 2.2Sorry the copy did not transfer to the PowerPoint very well!

Homework

ACE questions starting on page 38 #5-6 and page 2 of Mathematics warm-ups for CCSS, grade 7