Which of the following are necessary when proving that the opposite sides of a parallelogram are congruent? a. alternate interior angles are supplementary. b. opposite sides are parallel. c. opposite sides are perpendicular. d. alternate interior angles are congruent

First we have to understand what parallogram is .

A parallelogram is that quadrilateral, whose opposite sides are parallel and equal .

And alternate interior angles are congruent , not supplementary in parallelogram.

And neither the opposite sides are perpendicular .

So the correct option is B .

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.