## WEST BENGAL POLICE CONSTABLE MAINS ADMIT CARD DOWNLOAD

Candidates can dowloads there Admit card through the official website

WBP Constable mains exam willbe held in 30 th June 2019

**Click here**for download admit card

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__NUMBER SYSTEM__

__NUMBER SYSTEM__

__NATURAL NUMBERS__The counting numbers are 1,2,3,4,5,6,.... are called

__. The set of natural numbers is denoted by__

**natural numbers****N**.

Thus,

**N**={1,2,3,4,5,6,....}

__WHOLE NUMBERS__The set of natural numbers along with 0 represents

__. The set of whole numbers is denoted by__

**whole numbers****W**.

Thus,

**W**={0,1,2,3,4,5,.......}

__INTEGERS__The set of whole numbers along with the negatives of natural numbers represents

**. The set of integers is denoted by**

__integers__**I**or

**Z**.

Thus,

**I**or

**Z**={......,-3,-2,-1,0,1,2,3,......}

__RATIONAL NUMBERS__The numbers in the form p/q, where p and q are both integers, q not equal to 0 and p and q have no common factors except 1 i.e. p and q are co-prime, are called

**. The set of rational numbers is denoted by**

__rational numbers__**Q**.

Thus,

**Q**={p/q; p ,q belongs to Z , q not equal to 0}

__IRRATIONAL NUMBERS__The numbers which cannot be expressed in the form p/q , where p and q are both integers and q not equal to 0, are called irrational numbers.

__REAL NUMBERS__All rational and irrational numbers together called real numbers. The set of real numbers is denoted by

**R.**

__POLYGONS__The word polygon means having many sides. Therefore a closed plane figure made up of several line segments that are joined together is called a polygon.

For example, a triangle, a quadrilateral are polygons.

**NB**. A circle is not a polygon as it is not made of line segments.

**The number of diagonals in a polygon of sides n is n(n-3)/2**

__Diagonals:__

**Types of polygons**Regular polygons: A polygons having all angles and all sides are equal is called a regular polygon.

Irregular polygons: A polygon may have unequal angles and sides. Such polygons are called irregular polygon.

__Name of polygons according to their sides____Name__

__Number of sides__

Triangle 3

Quadrilateral 4

Pentagon 5

Hexagon 6

Heptagon 7

Octagon 8

Nonagon 9

Decagon 10

__Types of angle of a polygon__

**Interior Angle:**angle formed by two adjacent sides inside the polygon.

__Sum of Interior Angles in a Regular Polygon of Sides n is:__**(n-2) × 180 degree**

Exterior Angle: angle formed by two adjacent sides outside the polygon.

__Sum of Exterior Angles in a Regular Polygon of Sides n is:__

**360 degree**

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