Select the correct answer from each drop-down menu. Points A B and C form a triangle. Complete the statements to prove that the sum of the interior angles of AABC is 180°
Statement
Reason
Points A, B, and form a triangle.
given
Let DE be a line passing through B and parallel to AC. definition of parallel lines
23 = 25 and 21 = 24
m21 = m 24 and m23 = m 25
m24+ m2 + m25 = 180°
m2 1 + m2 2 + m23 = 180°
angle addition and definition of a straight line
substitution