Tricky Triangle!

1. Warm UP! 10 minutes Tricky Triangle! Shade in all multiples of 5. At the bottom of your activity sheet given a brief description of the pattern you see.

2. 4.2 Congruence and Triangles Objective: Identify congruent figures and corresponding parts

3. Congruent Figures ( B A ___ ___ ___ ___ ___ ___ )))) • 2 figures are congruent if they have the exact same size and shape. • When 2 figures are congruent the corresponding parts are congruent. (angles and sides) • Quad ABDC is congruent to Quad EFHG ___ ___ ___ ___ ))) (( D C F ( E ___ ___ ___ ___ ___ ___ )))) ___ ___ ___ ___ ))) (( H G

4. Example: Name the congruent angles and segments

5. Z • If Δ ABC is  to Δ XYZ, which angle is  to C?

6. Thm 4.33rd angles thm • If 2 s of one Δ are  to 2 s of another Δ, then the 3rd s are also .

7. Ex: find x ) ) 22o )) 87o )) (4x+15)o

8. Ex: continued 22+87+4x+15=180 4x+124=180 4x=56 x=14

9. Ex: ABCD is  to HGFE, find x and y. 9cm A B E 91o F (5y-12)o 86o 113o D C H G 4x-3cm 4x-3=9 5y-12=113 4x=12 5y=125 x=3 y=25

10. Thm 4.4Props. of Δs A • Reflexive prop of Δ - Every Δ is  to itself (ΔABC ΔABC). • Symmetric prop of Δ- If ΔABC ΔPQR, then ΔPQR ΔABC. • Transitive prop of Δ - If ΔABC ΔPQR & ΔPQR ΔXYZ, then ΔABC  ΔXYZ. B C P Q R X Y Z

11. AssignmentGeometry Workbookpg. 65-66

12. Warm Up: Angle Sum Theorem Task: Investigate the angle sum theorem Step 1: Draw a triangle ABC and cut out the three angles. Step 2: Rearrange the three angles to form a straight angle on a straight line. Step 3: Using COMPLETE sentences, explain why the angles form a straight line.