How To Construct A Rectangle Using A Compass.#Rectangle #toconstructrectangle#howtodraw #howtoconstruct#quadrilateral #geometry #trigonometry #technicaldrawing #engineeringdrawing. In Euclidean plane geometry, a rectangle is a rectilinear convex polygon or a quadrilateral with four right angles. It can also be defined as: an equiangular quadrilateral, since equiangular means that all of its angles are equal (360°/4 = 90°); or a parallelogram containing a right angle. A rectangle with four sides of equal length is a square. The term "oblong" is used to refer to a non-square rectangle.[1][2][3] A rectangle with vertices ABCD would be denoted as ABCD.