**Quadrilaterals** are shapes which have 4 straight sides. The sum of the interior angles of any quadrilateral add up to 360

## Special Types of QuadrilateralsEdit

### RectangleEdit

A rectangle is a quadrilateral which has 2 sets of parallel sides. All the angles in a rectangle are equal to 90. $ area=Length \times Width $

### SquareEdit

A square is a regular type of quadrilateral, and a special type of rectangle which has 4 equal sides. All the angles in a square are equal to 90

The area of a square can be worked out by squaring one of its lengths.

### ParallelogramEdit

a parallelogram is a quadrilateral with two sets of parallel sides. The opposite sides of a parallelogram are of equal length, and the opposite angles of a parallelogram are congruent.

$ Area = height \times base $

### TrapeziumEdit

A Trapezium is a quadrilateral which has 2 parallel sides of different lengths. Area of Trapezium = $ height \times \frac{a+b}{2} $

### RhombusEdit

A rhombus is a quadrilateral that has 4 sides of equal length, and whose opposite angles are equal. The area can be worked out by multiplying the two diagonals together and the dividing by 2.

$ Area= \frac {1}{2} \times D1 \times D2 $