Question

Points A,B, and C form a triangle. Complete the statements to prove that the sum of the interior angles of ABC is 180 degrees

Answer 1

Explanation:

Statements Reasons

1). Points A, B and C form the triangle 1). Given

2). Let DE be a line passing through 2). Definition of parallel lines

B and parallel to AC

3). ∠3 ≅ ∠5 and ∠1 ≅ ∠4 3). Theorem of Alternate

interior angles

4). m∠1 = m∠4 and m∠3 = m∠5 4). Definition of alternate angles

5). m∠4 + m∠2+ m∠5 = 180° 5). Angle addition and definition

of straight lines

6). m∠1 + m∠2+ m∠3 = 180° 6). Substitution