## Which one of the following statements is true only if ABCD are a parallelogram, and not any other?

Answer: A+C=180 (first answer choice) This statement is only true if and only if we are dealing with a rectangle (where all four angles are 90 degrees). The statement is false otherwise. Side Note: The second statement that AN=NC and DN=NB are true is because parallelograms have their diagonals running in the same direction.

## What proves that figure ABCD is a parallelogram?

If one pair of opposing sides of a quadrilateral have congruent and parallel sides, the quadrilateral can be called a parallelogram. The quadrilateral becomes a parallelogram if the diagonals of a quadrilateral intersect each other. ABCD is a parallelogram if — BD or — AC are adjacent.

**Which statement must be true if a parallelogram is not a rectangle? **

#2 A parallelogram that is not a square does not have four right angles or four congruent sides. It could have four right angles, but not four congruent sides. #1 must be false. To be square, it must first be rectangular.

### What do you mean by parallelogram?

A parallelogram is a type of quadrilateral with equal and opposite sides. Parallelogram-like shapes and objects are also common. Parametric properties. Parallelograms have opposite sides.

### What makes a parallelogram unique?

A parallelogram is a special type of polygon. It is a quadrilateral in which both sides of an opposite side are parallel. A rhombus is a parallelogram in which all sides are aligned. An isosceles trapezoid’s diagonals are always in line.

**How do you introduce a parallelogram? **

Parallelogram is the flat shape and a quadrilateral which has two opposite sides are parallel to each other. Parallelograms have the opposite length and angle. The measure of two angle in a parallelogram is 180deg so they are supplementary angles….