If 2 angles of one triangle are congruent to 2 angles of another triangle, then the third angles must be congruent to each other.

Question

If 2 angles of one triangle are congruent to 2 angles of another triangle, then the third angles must be congruent to each other.

True or false?

Answer 1

It is a THEOREM, which is PROVEN to be TRUE

Here is the proof:

1st triangle has angles A1,B1and C1

2nd triangle has angles A2.B2, and C2

angle A1 = angle A2

angle B1 = angle B2

Interior angles of triangle must total 180.

So then

A1 + B1 + C1 = 180 = A2 + B2 + C2

subtracts A1=A2 from both sides

B1+C1 = B2+C2

subtracts B1=B2 from both side

C1 =C2