ACT Preparation / Unit 13 ACT 1214 short lesson, about 20 seconds
Hypotenuse-Leg, and Two Tests That Fail
Captions available
The idea
Two right triangles are congruent if the hypotenuse and a leg match: the hypotenuse-leg test. Matching angles alone, AAA, prove only similarity, and SSA does not prove congruence.
In practice
Two triangles with angles of 50°, 60° and 70° can differ in size.
Where people slip
SSA works only in the right-triangle case, where it becomes hypotenuse-leg.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
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