Quadrilaterals are four sided polygons. Some quadrilaterals are probably quite familiar to you like squares and rectangles. A unique property of quadrilaterals is that the sum of all their interior angles always totals 360 degrees.
Types of quadrilaterals
A rectangle is a quadrilateral where all four angles are 90 degrees. A square is a special type of rectangle where all four sides are the same length.
A parallelogram is when both opposing pairs of sides on a quadrilateral are parallel. Squares and rectangles are also parallelograms.
A rhombus is a quadrilateral where all four sides have the same length. A square is a rhombus but not all rhombuses are squares.
A trapezoid is when there is only one pair of opposing parallel sides (see the picture below). An isosceles trapezoid is a trapezoid where the non-parallel sides are of equal length and it has a line of symmetry down the middle.