Question

Write a two column proof for the following conjecture. Statements and reasons

Given: parallelogram ABCD
Prove:
The image is a rhombus, the left side from top to bottom point is D and C. From the right side is A and B.

Answer 1

Information is given(reasons are in the parenthesis)

Angle A and angle B are supplementary. Angle B and Angle C are supplementary (given)


DC is parallel to AB (consecutive interior angles are supplementary )
BC is parallel to AD (consecutive interior angles are supplementary)

ABCD is a parallelogram (definition of parallelogram, has to pairs of parallel sides)