How to Calculate the Area of a Qaudrilateral

Calculating the area of a quadrilateral is an important skill in elementary mathematics. A quadrilateral is a 4-sided figure. We will consider three quadrilaterals whose opposite sides are parallel. Examples of quadrilaterals are squares, rectangles, and parallelograms. The area of a quadrilateral says how much space the object is covering.

What are the different types of quadrilateral?

A square is a 4-sided object where all sides are equal and all interior angles are 90°'s. It logically follows that opposite sides are parallel.

A rectangle is a 4-sided object where opposite sides are equal and all interior angles are 90°'s. It logically follows that opposite sides are parallel.

A parallelogram is a 4-sided object where opposite sides are equal and that opposite interior angles are equal. It logically follows that opposite sides are parallel.

How are the square, rectangle and parallelogram related?

Squares are a type or rectangle. Rectangles are a type of parallelogram. By the transitive property, all squares are parallelograms. It should be mentioned that rectangles are not squares, parallelograms are not rectangles, and parallelograms are not squares.

What is the formula needed to calculate area of a quadrilateral?

All quadrilaterals have the same formula, which is length times height (A = L*H). Sometimes this formula gets simplified to length times width (A = L*W), but width and height are really the same thing here.

Let's look at some examples.

1) What is the area of the square whose side is 5 cm?

A = L*W
A = 5 cm*5 cm
A = 25 cm²

2) What is the area of a rectangle whose length is 3 feet and whose width is 4 feet?

A = L*W
A = 3 feet*4 feet
A = 12 feet²

3) What is the area of a parallelogram whose length is 10 inches and whose height is 5 inches?

A = L*H
A = 10 inches*5 inches
A = 50 inches²