Quadrilaterals are 4 sided, 4 angled shapes that are always closed in. All of the sides of a quadrilateral are straight and the sum of all the angles add up to 360 degrees. There are 6 special kinds of quadrilaterals; kite, rhombus, square, rectangle, parallelogram, and trapezoid. Sometimes they are called "quadrangles" or "tetragons." This type of quadrilateral are one angle greater than 180 degree.