A rectangle is a two-dimensional closed figure with four sides and four right angles. The word rectangle can in fact be broken into two words: rect and angle.
The word rect comes from the Latin word rectus meaning right or straight. The word rectangle therefore is referring to the fact that the rectangle must have a right angle. The following figure is a rectangle.
Opposite sides are parallel
Opposite sides are equal
Each of the interior angle is equal to 90 degrees
The sum of all interior angles is 360 degrees.
The four right angles are shown with the special red symbol and the sides that are parallel and equal are shown with the same amount of green markings.