Based on the information in the diagram, can you prove that the figure is a parallelogram? explain.
a. no; you cannot prove that the quadrilateral is a parallelogram.
b. yes; two opposite sides are both parallel and congruent.
c. yes; the diagonals are congruent.
d. yes; the diagonals bisect each other.

There is no diagram present. So I will just state the properties of a parallelogram.

A parallelogram is:
1) a flat shape
2) opposite sides are parallel
3) opposite sides are equal in length
4) opposite angles are equal
5) angles of the same side are supplementary angles meaning the sum of the angles equal to 180°
6) diagonals bisect each other

Examples of parallelograms are square, rectangle, and rhombus.

No a triangle cannot be formed because when you add the two smallest number together (which would be 11) the have to be bigger than the number it is "against" ( which would be 12)