Quadrilateral vs. Trapezium

Attribute	Quadrilateral	Trapezium
Number of sides	4	4
Number of angles	4	4
Sum of interior angles	360 degrees	360 degrees
Opposite sides parallel	No	Yes
Diagonals bisect each other	Yes	Yes

Definition

A quadrilateral is a polygon with four sides and four angles. It is a closed figure with straight sides. A trapezium, on the other hand, is a specific type of quadrilateral with at least one pair of parallel sides. The parallel sides are called the bases of the trapezium, while the non-parallel sides are called the legs.

Properties

Quadrilaterals have various properties that distinguish them from other polygons. Some of the key properties of quadrilaterals include having four vertices, four angles, and four sides. Additionally, the sum of the interior angles of a quadrilateral is always 360 degrees. Trapeziums share these properties with quadrilaterals, but they also have the unique property of having at least one pair of parallel sides.

Types

There are different types of quadrilaterals, each with its own set of properties. Some common types of quadrilaterals include squares, rectangles, parallelograms, and rhombuses. Each type has specific characteristics that set it apart from the others. Trapeziums, on the other hand, are a specific type of quadrilateral that have at least one pair of parallel sides. They can be further classified into isosceles trapeziums, where the non-parallel sides are equal in length, and right trapeziums, where one angle is a right angle.

Angles

One of the key differences between quadrilaterals and trapeziums lies in their angles. In a quadrilateral, the sum of the interior angles is always 360 degrees. This means that the angles can vary in size and measure, but their sum will always be constant. In a trapezium, the sum of the interior angles is also 360 degrees, but the presence of parallel sides affects the angles. The angles opposite each other on the parallel sides are called corresponding angles, and they are equal in measure.

Diagonals

Both quadrilaterals and trapeziums have diagonals, which are line segments that connect two non-adjacent vertices. In a quadrilateral, there are two diagonals that can be drawn, and they intersect at a single point called the centroid. The diagonals of a quadrilateral bisect each other, meaning they divide each other into two equal parts. In a trapezium, the diagonals are not necessarily equal in length, but they still intersect at a single point within the trapezium.

Area and Perimeter

The area and perimeter of a quadrilateral or trapezium can be calculated using different formulas based on their properties. The area of a quadrilateral can be calculated by dividing it into triangles and using the formula for the area of a triangle. The perimeter of a quadrilateral is simply the sum of its four sides. In the case of a trapezium, the area can be calculated using the formula A = 1/2 * (a + b) * h, where a and b are the lengths of the parallel sides and h is the height. The perimeter of a trapezium is the sum of all its sides.

Applications

Both quadrilaterals and trapeziums have various applications in real life. Quadrilaterals are commonly used in architecture and construction to design buildings and structures. They are also used in geometry and mathematics to study the properties of shapes. Trapeziums are often used in engineering and design to create stable structures with parallel sides. They are also used in trigonometry to calculate angles and distances in various applications.