Download 4.1

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
FIGURES
12/3
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