PLEASE CHECK IF IT IS A OR D

Question

John writes the proof below to show that the sum of the angles in a triangle is equal to 180 degree

Given: XY intersects ABC at

vertex C and is parallel

to AB

Prove: m<1 + m<2 + m2<3 =180°

Proof:

Statements

1. XY// AB,

2.m<4+ m<2 + m<5 =180°

3. m<4 ≅<1;<5≅ <3

4.M<4 =m<1;m<5=m<3

5. m<1 +m<2+ m<3 =180

Which of these reasons would John NOT need to use in his proof?

A, The sum of the angles on one side of a straight line is 180 degree

B,If a statement about a is true and a = b, the statement formed by replacing a with b is also true.

C, When two parallel lines are cut by a transversal, the resulting alternate interior angles are congruent.

D,When two parallel lines are cut by a transversal, the resulting alternate exterior angles are congruent.

Answer 1