What is a four sided figure with opposite sides parallel but angles that are not right angles?

A four-sided figure with opposite sides parallel and angles that are not right angles is characterized as a rhomboid. In geometry, a rhomboid is defined as a parallelogram where adjacent angles are unequal, distinguishing it from rectangles and squares, which have right angles.

The defining feature of a rhomboid is that while opposite sides are equal in length and parallel, the angles can vary, leading to a more oblique appearance. This makes it different from shapes like rectangles and squares that always have right angles. A rhombus, while also having parallel opposite sides and equal-length sides, has angles that are not right angles but can also be considered as a specific type of rhomboid where all sides are equal. However, in the context of the question, the term rhomboid is most applicable since it emphasizes the parallel and unequal angle relationships without the constraint of equal side lengths.