Polygons A closed figure bounded by n straight lines is called a polygon. Regular polygons A polygon whose all sides are equal is called a regular polygon. Formulae related to polygons Sum of all interior angles of a polygon of Read More …

# Month: April 2017

## Geometry ( triangles)

Triangle Triangle: A closed figure bounded by three straight lines is called a triangle. A triangle has three vertices Read More …

## Simplification (BODMAS ,powers and surds )

BODMAS – ( bracket of division multiplication addition and subtraction) Step 1 – First of all solve brackets Step 2 – After that solve powers and surds ( squares , cubes , square root , cube root etc.) Step 3 Read More …

## Number System ( divisibility rule and remainder theorem)

Natural numbers : 1, 2, 3, 4, 5, ……………………… Whole numbers : 0, 1, 2, 3, 4, 5, …………………. Integers : …………….,-3, -2, -1, 0, 1, 2, 3, 4, 5, …………………. Rational numbers : Numbers which can be written in the form [latex]\frac{p}{q}[/latex], where p Read More …

## Mensuration ( area of circle )

Circle Circle is the set of all points which are equidistant from the fixed point . The fixed point is called the center of circle and the distance from the centre to the point of circle is called radius Circumference of Read More …

## Mensuration (Area of 2- dimensional geometry)

Triangle Perimeter of triangle : [latex]\frac{a+b+c}{2}[/latex] Area of triangle = [latex]\sqrt{s\times(s-a)\times(s-b)\times(s-c)}[/latex] where s = [latex]\frac{a+b+c}{2}[/latex] Area of triangle = [latex]\frac{1}{2}\times base\times height[/latex] = [latex]\frac{1}{2}\times b\times h[/latex] Equilateral triangle Area of equilateral triangle = [latex]\frac{\sqrt{3}}{4}\times a^{2}[/latex] Height of equilateral triangle = [latex]\frac{\sqrt{3}}{2}\times Read More …

## Area of triangle using Sine and Cosine law:

Sine law : If a, b and c are the sides of a triangle opposite to the angles A, B and C then [latex]\frac{sinA}{a}[/latex] = [latex]\frac{sinB}{b}[/latex] = [latex]\frac{sinC}{c}[/latex] Cosine law : cosA = [latex]\frac{b^{2} + c^{2} – a^{2}}{2bc}[/latex] cosB = [latex]\frac{a^{2} Read More …

## Real Numbers

Real Numbers Euclid’s division lemma : For any two positive integers a and b , there exist unique integers q and r such that a = bq + r, Read More …