Answer:
Option (3) from the top.
Step-by-step explanation:
Statements Reasons
1). m∠1 + m∠2 + m∠3 = 180° 1). The angles form a line
2). m∠A = m∠2 2). Alternate interior angles are equal.
3). m∠3 = m∠B 3).Because corresponding angles are equal.
4). m∠1 + m∠A + m∠B = 180° 4). Substitution
Hence, sum of the interior angles of a triangle is 180°.
Therefore, option (3) from the top will be the correct option.
