I need help on a geometry proof!!!!

Question

If Line AB is parallel to Line DC and Line BC is parallel to line AD, prove that angle B is congruent to angle D.

The picture is basically a square or parallelogram with line DC on the Top and Line AB on the bottom, and as u can tell A and D connect to form a line and C and B connect to form a line.
HELP I don't understand proofs at all, and have a test soon!!!!!!!!!!

Answer 1

Let ABCD be a quadrilateral such that the pair of opposite sides AB and CD are equal
and parallel to each other
We need to show that AD and BC are parallel to each other. Consider the two triangles ABD and CDB, we have
AB = CD (given)
�ÚABD = �ÚCDB (alt. int. �Ús of // lines AB and CD)
BD = DB
Hence ƒ¢ABD ≅ ƒ¢CDB (S.A.S.)
and �ÚADB =�ÚCBD (corresponding �Ús of congruent triangles) �ˆ AD // BC (theorem 2.5(i):
converse of alt. int. �Ús of // lines) This completes the proof of this theorem

Answer 2

Indicate in standard form the equation of the line through the given points.

P(0, -4), Q(5, 1)

Answer 3

How to find the length of EC
Give your answer to the nearest cm