Explain why parallelograms are always quadrilaterals, but quadrilaterals are sometimes parallelograms.

quadrilaterals have exactly four sides of any length
parallelograms have two pairs of parallel sides and each pair of sides has the same length for both of its sides

Answer Link

JeanaShupp JeanaShupp · Answer 2 · 2020-01-09T04:03:19+01:00

Answer: Parallelogram is a kind of quadrilateral where as there are some quadrilaterals (like trapezoid , kite, .. ) that do not satisfy the properties of parallelograms.

Step-by-step explanation:

A quadrilateral is a closed polygon having fours sides.

A parallelogram is a kind of quadrilateral having following properties:

Its opposite sides and opposite angles are equal.
The sum of adjacent angles is 180°.
The diagonal of parallelogram bisect each other.

A Trapezoid is also a quadrilateral . It has only one pair of parallel sides. (The other one are not parallel).

So , all quadrilaterals not parallelograms.

Therefore, parallelograms are always quadrilaterals but quadrilaterals are sometimes parallelograms because parallelogram is a kind of quadrilateral where as there are some quadrilaterals (trapezoid , kite, .. ) ) that do not satisfy the properties of parallelograms.