1. Lucas Dougherty

2. Ch. 7-3 Congruent Polygons
Congruent Polygons are polygons that have the same size and shape. When two polygons are congruent, you can slide, flip, or turn one so that it fits exactly on top of the other one.
-Corresponding angles and corresponding sides of congruent polygons are congruent.
Example:
Similar Polygons – have same shape but not same size. Prove similar by using proportions.
950
950
Example 1: Write a congruence statement for the congruent figures below.
Angle A is congruent to angle E
Angle B is congruent to angle F
Angle C is congruent to angle D D A B E F C

3. Showing Triangles are Congruent
To demonstrate that two triangles are congruent, show that the following parts of one triangle are congruent to the corresponding parts of the other triangle.
Side-Side-Side Side-Angle-Side Angle-Side-Angle
(SSS) (SAS) (ASA) 2 2 1 1 1 1
-The order of the angles and sides is important in deciding whether two triangles are congruent.

4. The two triangles are congruent by SAS or Side-Angle-Side
Example 2: Show that each pair of triangles is congruent. State which rule you used: SSS, SAS, ASA
The two triangles are congruent by SAS or Side-Angle-Side 1 1 2
The two triangles are congruent by ASA or Angle-Side-Angle 1 1 2

5. Both triangles share the side in the middle so mark that congruent.
Example 3: Show that each pair of triangles is congruent. State which rule you used: SSS, SAS, ASA A
Both triangles share the side in the middle so mark that congruent.
The triangles are congruent by SAS or Side-Angle-Side D B C A
550
Triangle ABC is congruent with triangle EDC
Find the measure of angle DEC and ECD. C
350 D
DEC = 550 and ECD = 350 B E

6. Homework
Pg 314 #2-26 evens - just the answer