It is sometimes true that two parallelograms are similar. The could be congruent, or dissimilar in that one is not an enlargement of the other.
Sometimes * * * * * Never. A parallelogram has two pairs of equal angles opposite one another. A trapezoid does not.
A quadrilateral always has four sides.A square always has four sides→ a square is always a quadrilateral.A quadrilateral's only distinguishing feature is a shape with four sides.A square has four sides, but also those four sides must all be the same length and all the angles are the same, at 90o.So squares are always quadrilaterals, but quadrilaterals are only sometimes squares.
It depends on whether you consider rectangles and other parallelograms to be forms of trapezoids.If a rectangle can be considered a special case of a trapezoid (UK trapezium), and an isosceles trapezoid is modified so that any of its angles is 90 degrees, then it is a rectangle. In other words, it becomes a trapezoid with all right angles.However, you can also consider that trapezoids and parallelograms are two different kinds of quadrilaterals: trapezoids having one set of parallel sides and parallelograms having two sets. Then a trapezoid can never be a rectangle, or it would just be called a rectangle.
Never
Sometimes they are.
Parallelograms are squares is sometimes true. Squares are parallelograms is always true. Rhomboids are parallelograms is also always true. So not all parallelograms are squares but some are.
why
Properties of quadrilaterals
A rhombus is always in the same class as 4 sided quadrilaterals because it too has 4 sides
Never but they are both quadrilaterals because they have 4 sides
Never but they are both quadrilaterals because they have 4 sides
Never but they are both quadrilaterals because they have 4 sides
It is sometimes true that two parallelograms are similar. The could be congruent, or dissimilar in that one is not an enlargement of the other.
A trapezoid is never a kite but they are both 4 sided quadrilaterals
A trapezoid is never a rectangle but they are both 4 sided quadrilaterals
A kite is never a square but they are both 4 sided quadrilaterals