2. (03.01 LC)
Keaton wrote the following paragraph proof for the Vertical Angles Theorem:
N
The sum of angle 1 and angle 4 and the sum of angle 3 and angle 4 are each equal to 180 degrees .
The sum of angle 1 and angle 4
the sum of angle: and angle 4 by the transitive property of equality. Angle 1 is equal to angle 3 by the subtraction property of equality.
Which phrase completos the proof? (6 points)
O by construction using a straightedge
© by the definition of a perpendicular bisector