Answer:
No, rhombuses are not necessarily rectangles. While both shapes are quadrilaterals with opposite sides parallel, there is an additional requirement for a rectangle that is not present in a rhombus. Specifically, a rectangle must have all interior angles measuring 90 degrees, while a rhombus can have any angle between 0 and 180 degrees.
On the other hand, all rectangles are parallelograms, while not all parallelograms are rectangles. Similarly, all squares are both rhombuses and rectangles, but not all rhombuses or rectangles are squares. In summary, a rhombus is a quadrilateral with four equal sides, while a rectangle is a quadrilateral with four right angles. While there is some overlap between the definitions, they are not equivalent.