Different forms of forms differ from each various other in terms of sides or angles. Many kind of shapes have 4 sides, but the difference in angles on their sides provides them distinctive. We contact these 4-sided shapes the quadrilaterals.

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In this article, you will certainly learn:

What a quadrilateral is.How the various types of quadrilaterals look choose.The properties of quadrilaterals.


What is a Quadrilateral?

As the word argues, ‘Quad’ indicates 4 and also ‘lateral’ suggests side. Therefore a quadrilateral is a closed two-dimensional polygon comprised of 4-line segments. In basic words, a quadrilateral is a shape through 4 sides.

Quadrilaterals are everywhere! From the publications, chart records, computer keys, tv, and mobile display screens. The list of real-civilization examples of quadrilaterals is endless.

Types of Quadrilaterals

Tbelow are six quadrilaterals in geometry. Several of the quadrilaterals are sudepend acquainted to you, while others may not be so familiar.

Let’s take a look.


 A rectangle

A rectangle is a quadrilateral via 4 ideal angles (90°). In a rectangle, both the pairs of oppowebsite sides are parallel and also equal in size.


Properties of a rhombus

All sides are congruent by definition.The diagonals bisect the angles.The diagonals in a kite bisect each other at appropriate angles.


Properties of Quadrilaterals

The properties of quadrilaterals include:

Eextremely quadrilateral has 4 sides, 4 vertices, and also 4 angles.4The complete meacertain of all the four interior angles of a quadrilateral is constantly equal to 360 levels.The amount of inner angles of a quadrilateral fits the formula of polygon i.e.

Sum of inner angles = 180 ° * (n – 2), wbelow n is equal to the variety of sides of the polygon

Rectangles, rhombus, and also squares are all forms of parallelograms.A square is both a rhombus and a rectangle.The rectangle and also rhombus are not square.A parallelogram is a trapezium.A trapezium is not a parallelogram.Kite is not a parallelogram.

Category of quadrilaterals

The quadrilaterals are classified right into 2 standard types:

Convex quadrilaterals: These are the quadrilaterals with inner angles much less than 180 levels, and also the two diagonals are inside the quadrilaterals. They include trapezium, parallelogram, rhombus, rectangle, square, kite, etc.Concave quadrilaterals: These are the quadrilaterals with at leastern one inner angle better than 180 degrees, and at leastern one of the two diagonals is outside the quadrilaterals. A dart is a concave quadrilateral.

There is one more less widespread form of quadrilaterals, called facility quadrilaterals. These are crossed numbers. For instance, crossed trapezoid, crossed rectangle, crossed square, and so on.

Let’s occupational on a few instance troubles about quadrilaterals.

Example 1

The interior angles of an irconsistent quadrilateral are; x°, 80°, 2x°, and 70°. Calculate the value of x.


By a building of quadrilaterals (Sum of interior angles = 360°), we have,

⇒ x° + 80° + 2x° + 70° =360°


⇒ 3x + 150° = 360°

Subtract 150° on both sides.

⇒ 3x + 150° – 150° = 360° – 150°

⇒ 3x = 210°

Divide both sides by 3 to get;

⇒ x = 70°

Thus, the worth of x is 70°

And the angles of the quadrilaterals are; 70°, 80°, 140°, and 70°.

Example 2

The interior angles of a quadrilateral are; 82°, (25x – 2) °, (20x – 1) ° and (25x + 1) °. Find the angles of the quadrilateral.


The complete sum of inner angles of in a quadrilateral = 360°

⇒ 82° + (25x – 2) ° + (20x – 1) ° + (25x + 1) ° = 360°

⇒ 82 + 25x – 2 + 20x – 1 + 25x + 1 = 360


⇒ 70x + 80 = 360

Subtract both sides by 80 to get;

⇒ 70x = 280

Divide both sides by 70.

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⇒ x = 4

By substitution,

⇒ (25x – 2) = 98°

⇒ (20x – 1) = 79°

⇒ (25x + 1) = 101°

Thus, the angles of the quadrilateral are; 82°, 98°, 79°, and also 101°.

Practice Questions

Consider a parallelogram PQRS, whereFind the 4 inner angles of the rhombus whose sides and one of the diagonals are of equal size.