Please help! Angles 1 and 2 are vertical angles, and angles 1 and 3 form a linear pair. Prove that angle 2 and 3 are supplementary angles

Answer 1

angle 1 and 2 are vertical angles given

angles 1 and 2 are equal property of vertical angles

angles 1 and 3 form a linear pair given

angles 1 and 3 are supplementary definition of a linear pair

angles 2 and 3 are supplementary substitution (of equal angle 2 for 1)