Warm-Up• Complete the Statement:When parallel lines are cut by a transversal,

• Alternate Interior Angles are ___________• Same Side Interior Angles are__________• Corresponding Angles are__________

4.1 CONGRUENT FIGURES12/3

Learning Target

I can identify the corresponding parts of congruent figures

Vocabulary

Congruent Polygons – Have congruent corresponding parts (sides and angles)

Notes

IMPORTANT: When naming congruent polygons, you must list the vertices in the same order.

ABCD ≅ EFGH

Practice

•Name the congruent polygons and find the measures of the numbered angles.

Practice

Do 2 and 3 on the 4-1 worksheet.

Naming Congruent Parts

You need to be able to name congruent corresponding parts of congruent polygons…so you need to pay attention to the vertices in the name of the polygon

Practice

Practice

Practice

Do 6 and 7 on the 4-1 worksheet.

Deciding if figures are congruent

• If you can show that all corresponding sides and angles are congruent, then the figures will be congruent.

Important to Remember

•Vertical Angles are congruent.• If two angles of one triangle are congruent to two angles of another triangle, then the third angles are congruent.

Practice

Is triangle GHJ congruent to triangle IHJ? Explain why.

Practice

Is triangle RSQ congruent to triangle VTS? Explain why.

Practice Together

#10 on the 4-1 worksheet.

Recap

•Naming Congruent Polygons (1-3)•Find missing values of congruent polygons (1-3)

•Name corresponding parts of congruent polygons (4-7)

•State whether 2 figures are congruent or not (8-9)

•Provide reasons in proofs