A parallelogram is a four-sided figure with parallel opposite sides that are equal in length. Some examples of parallelograms are rectangles, squares and rhombuses. Parallelograms can further be described by the type of angles their corners create, whether oblique or right. Another property of a parallelogram is that the diagonals of parallelograms bisect each other.
An oblique angle is an angle that is not 90 degrees or a multiple of 90 degrees. Ninety-degree angles are called right angles. Oblique angles can either be acute or obtuse. An acute angle is an angle measuring less than 90 degrees, while an obtuse angle measures more than 90 degrees. Another property of a parallelogram to remember is that the consecutive angles add up to 180 degrees, or are supplementary. Consecutive angles are angles that are at each end of one side.
A rhombus is a parallelogram with four equal sides and four oblique angles. If this shape has four right angles, it is a square. The consecutive angles of a rhombus equal 180 degrees, which is how you can be sure that this shape is an oblique-angled parallelogram. If you turn this shape onto one of its corners, it would look like a diamond.
A rhomboid is a parallelogram with adjacent sides of unequal length and four oblique angles. If this shape has four right angles, it is a rectangle. The consecutive angles of a rhomboid equal 180 degrees, which is how you can be sure that this shape is an oblique-angled parallelogram. An oblique-angled parallelogram may sometimes be referred to as a rhombus.