Answer:
D. Sum of Interior angles; Converse of opposite angles theorem.
Explanation:
Solution:
Statement Reasons
1. m∠A =50°,m∠B= 130°,m∠C = 50° Given
Now we know that;
"Sum of all interior angles is 360°."
2. m∠A + m∠B + m∠C + m∠D =360° Sum of all Interior angles
3. 50°+ 130° + 50° + m∠D =360° Substitution
4. m∠D =130° Subtraction property of equality.
5. m∠A Congruent m∠C Angles with equal measure are congruent m∠B Congruent m∠D
Now By Converse of opposite angle theorem which states that;
"If the opposite angles of a quadrilateral are congruent, then the figure is a parallelogram."
6. ABCD is Parallelogram Converse of opposite angle theorem