Quadrilaterals are four sided, two-dimensional shapes. Each side has to be a straight line, even if it looks diagonal in accordance to the other sides. Three examples include squares, rectangles, and parallelograms.
Many different types of quadrilaterals can have three equal side lengths. as long as it is a closed shape that has four sides, it is considered a quadrilateral, but not all quadrilaterals have names. A triangle with three equal side length would be called an equilateral triangle.
quadrilaterals are any four sided figure, as long as their sides are straight and the shape is closed. Types of quadrilaterals include trapezoids, squares, kites, rhombuses, rectangles and parallelograms. Get an A in geometry!