SAT Math: Congruent Triangles
16+ practice questions in Praczo
The concept, explained
- 1
Two triangles are congruent if they are exactly the same size and shape (all corresponding sides and angles are equal).
- 2
You can prove congruence using standard postulates: SSS, SAS, ASA, AAS, and HL (Hypotenuse-Leg for right triangles).
- 3
AAA (Angle-Angle-Angle) proves similarity, not congruence (one triangle could be a scaled-up version of the other).
- 4
SSA (Side-Side-Angle) is NOT a valid congruence postulate (unless it's HL for right triangles).
- ✗ Assuming two triangles are congruent just because they look identical in the diagram.
- ✗ Using SSA to incorrectly assume congruence.
SAT-style practice
In triangles ABC and DEF, AB = DE, Angle B = Angle E, and BC = EF. Which postulate proves the triangles are congruent?
Ready to master this concept?
Praczo tracks your mastery on all 179 SAT concepts — not just broad topics. One sample question is a start; drilling to mastery is how scores move.
3-day free trial — no credit card required