What must the measure of Angle A for this quadrilateral to be a parallelogram

[15 points, algebra 2]simplify the complex fraction and find the restrictions.

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.

In a 45-45-90 right triangle, what is the ratio of the length of one leg to the length of the other leg? а . 1: 2 в. 2: 1 с. 2: 1 d. 1: 1