Select the correct answer from each drop-down menu. D
4
Points A, B, and C form a triangle. Complete the statements to prove that the sum of the interior angles of AABC is 180°.
given
Statement
Reason
Points A, B, and Cform a triangle.
Let DE be a line passing through B and parallel to AC. definition of parallel lines
23 - 25 and 21 - 24
m_1 = m 4 and m23 = m_5
m24+ m_2 + 25 = 180°
m 1 + m2 + m 3 = 180°
angle addition and definition of a straight line
substitution