A rhombus does not necessarily have 90-degree angles. A rhombus is a type of quadrilateral where all four sides are of equal length. The angles in a rhombus can vary, but opposite angles are always equal. If a rhombus has 90-degree angles, it is a special case known as a square.
In summary, while a rhombus can have 90-degree angles (making it a square), it is not a requirement for all rhombuses. The defining characteristic of a rhombus is that all sides are equal in length, not the measure of its angles.