Answer:
A parallelogram is a quadrilateral that has two parallel and equal pairs of opposite sides.
From the given diagram,
Given: AD = BC and AD || BC, then:
i. AB = DC (both pairs of opposite sides of a parallelogram are congruent)
ii. <ADC = < BCD and < DAB = < CBA
thus, AD || BC and AB || DC (both pairs of opposite sides of a parallelogram are parallel)
iii. < BAC = < DCA (alternate angle property)
iv. Join BD, line AC and BC are the diagonals of the quadrilateral which bisect each other. The two diagonals are at a right angle to each other.
v. <ADC + < BCD + < DAB + < CBA = (sum of angles in a quadrilateral equals 4 right angles)
Therefore, ABCD is a parallelogram.
Step-by-step explanation:
