Proving Triangles Are Congruent…part 1 Section 4.2

Yesterday, in attempting to show 2 triangles were congruent, we said the following … WELL, MR. D LIED TO YOU ! -sort of -

The “SSS Post.” shows that basically As it turns out, you really don’t need all that information to prove 2 triangles are congruent… The “SSS Post.” shows that basically all we need to have congruent triangles is 3 corresponding side-pairs congruent.

Before attempting to prove this, ask yourself…with respect to both triangles, what common side do they share ? Therefore, what must be true about that common side’s length vs. itself ? TRY TO PROVE IT, THEN CLICK NEXT

Statements Reasons GIVEN Reflexive prop. of congruence SSS. Post. 1. 2. 3. 1. 2. 3.

Another short-cut to show triangle congruence Basically you need to demonstrate that there are 2 pairs of corresponding congruent sides, with the angle in between them also congruent (included angle).

Statements Reasons GIVEN Alt. Int <‘s Thm. Reflexive prop. of Prove: Attempt it, then click to see Statements Reasons GIVEN Alt. Int <‘s Thm. Reflexive prop. of SAS post. 1. 2. 3. 4. 1. 2. 3. 4.

Now complete packet pg 2