Which of the following statements is not correct? a every square is a parallelogram b every parallelogram is a rectangle c every rhombus is a parallelogram d every rectangle is a parallelogram

A. A square is a special type of parallelogram, so every square is a parallelogram. A. is true.

B. Every parallelogram has two sets of opposite sides parallel, but not all angles are right angles. Only some parallelograms are rectangles, not all. B. is false.

C. A parallelogram with 4 congruent sides is a rhombus. A rhombus is a special type of parallelogram, so every rhombus is a parallelogram. C. is true.

D. A rectangle is a special type of parallelogram, so every rectangle is a parallelogram. D. is true.