Congruent or Similar or Neither?

SIMILAR

• What does it mean for triangles to be similart?
• Their angles must all be congruent.
• Their corresponding sides must be proportional.

CONGRUENT

• What is required for triangles to be congruent?
• All angles must be congruent.
• Corresponding sides must be proportional with a scale factor of one. (What does that men exactly?)

BUT HOW MUCH DO WE HAVE TO KNOW?

• There are several sets of information that are sufficient to prove either similarity or congruence.
• We do not have to know all three angles and all three pairs of sides.
• We will look at this in more detail later, but here's a preview:
• For similarity, the conditions are SSS, AA and SAS.
• For congruence, they are SSS, SAS, ASA, and AAS.

THINK ABOUT IT!