
AA
A method for proving similarity of triangles: if two angles are
congruent to their
corresponding parts in another triangle, then the triangles are similar.

AAS
A method for proving congruence of triangles: if two angles
and a side not
included by those angles are congruent to their corresponding parts in
another triangle, then the triangles are congruent.

ASA
A method for proving congruence of triangles: if two angles
and their
included side are congruent to their corresponding parts in another
triangle, then the triangles are congruent.

Congruent Triangles
Triangles whose corresponding angles and sides are all congruent.

Congruent Polygons
Polygons whose corresponding sides and interior angles are all
congruent.

Corresponding Parts
The angles or sides in a polygon organized such that each angle and each side
coincides with exactly one angle or side in another polygonthe pairs of angles
and sides in each polygon are called corresponding parts.

HypotenuseLeg
A method for proving congruence of
right triangles: if one
leg and the
hypotenuse are congruent to their
corresponding parts in another right triangle, the right triangles are
congruent.

SAS
A method for proving congruence or similarity of
triangles: if two sides
are congruent or proportional and their included angle is congruent to their
corresponding parts of another triangle, then the triangles are congruent or
similar, respectively.

Similar Triangles
Triangles whose corresponding angles are
congruent and whose corresponding sides are
proportional. Congruence is a subset of similarity.

SSS
A method for proving the congruence or similarity of
triangles: if the
three sides of a triangle are congruent to their corresponding parts, then
the triangles are congruent. If the three sides of a triangle are proportional
to their corresponding parts in another triangle, then the triangles are
similar.