Answer:- The third option is the right answer" In a parallelogram opposite sides are congruent.
Explanation:-
A parallelogram is a simple quadrilateral whose opposite sides are parallel and have equal length.The opposite angles of a parallelogram have equal measure.
Now,
- First conjecture is wrong as in a parallelogram consecutive sides may not be equal ,if they are equal then it can be rhombus.
- Second conjecture is wrong as in a parallelogram opposite sides are equal.
- Third conjecture is true by the definition of parallelogram.
- Fourth conjecture is wrong as in a parallelogram opposite sides are parallel thus it cannot bisect each other.