Given: angle 1 and angle 2 form a linear pair, Proven: angle 2 and angle 3 are supplementary

Look at the proof down

Step-by-step explanation:

The given is;

→ ∠1 and ∠2 form a linear pair

→ ∠1 ≅ ∠3

We want to prove;

→ ∠2 and ∠3 are supplementary

We will write the proof in like a table

1. ∠1 and ∠2 formed a linear pair  ⇒  1. Given

2. m∠1 + m∠2 = 180°  ⇒ 2. Sum of angles on a straight line

3. ∠1 and ∠2 are supplementary angles  ⇒  3. Supplementary angles add up to 180°

4. ∠1 ≅ ∠3  ⇒  4. Given

5. m∠2 + m∠3 = 180°  ⇒  5. Substitution method

6. ∠3 is a supplement of ∠2  ⇒  6. Supplement of equal angles

7. ∠2 and ∠3 are supplementary  ⇒  7. Proved

answer: the first graph

step-by-step explanation: