"CPCT" is an acronym that stands for Corresponding Parts of Congruent Triangles.

In geometry, when two triangles are congruent (meaning they have the same size and shape), their corresponding parts are also congruent.

For example, if you have two congruent triangles ABC and DEF, you can say that:

• Angle A is congruent to angle D (corresponding angles).
• Side AB is congruent to side DE (corresponding sides).
• And so on for all corresponding parts of the triangles.

CPCT is one of the fundamental principles used in geometry along with other triangle congruence criteria, such as SSS (Side-Side-Side), SAS (Side-Angle-Side), ASA (Angle-Side-Angle), and AAS (Angle-Angle-Side).