Question

how to use c.p.c.t tell me

Answer 1

CPCTC is an acronym for corresponding parts of congruent triangles are congruent. CPCTC is commonly used at or near the end of a proof which asks the student to show that two angles or two sides are congruent. It means that once two triangles are proven to be congruent, then the three pairs of sides that correspond must be congruent and the three pairs of angles that correspond must be congruent.

Answer 2

Hello...

This is a property for pair of congruent triangles.

Think pair of congruent triangles ABC and PQR.

∆ABC ≅ ∆PQR

So, by using the property C.P.C.T.
(Corresponding Parts of Congruent Triangles)

AB = PQ,
BC = QR,
AC = PR,
∠ABC = ∠PQR,
∠BAC = ∠QPR, and ∠ACB = ∠PRQ