# Straight Line

## Collinearity of Points

Here you will learn condition for the collinearity of points with examples. Let’s begin – Collinearity of Points If the given points lie in the same line, then the given points are collinear otherwise they are non-collinear. Condition for collinearity of three given points Three given points A($$x_1,y_1$$), B($$x_2,y_2$$) and C($$x_3,y_3$$) are collinear if any …

## Equation of Line Parallel to a Line

Here you will learn what is the equation of line parallel to a given line with examples. Let’s begin – Equation of Line Parallel to a Line The equation of the line parallel to a given line ax + by + c = 0 is ax + by + $$\lambda$$, where $$\lambda$$ is a constant. …

## Equation of a Line Perpendicular to a Line

Here you will learn what is the equation of a line perpendicular to a line with proof and examples. Let’s begin – Equation of a Line Perpendicular to a Line The equation of a line perpendicular to a given line ax + by + c = 0 is bx – ay + $$\lambda$$ = 0, …

## Normal Form of a Line Equation

Here you will learn normal form of a line equation with proof and examples. Let’s begin – Normal Form of a Line (Perpendicular form of line) The equation of the straight line upon which the length of of the perpendicular from the origin is p and this perpendicular makes an angle $$\alpha$$ with x-axis is …

## Intercept Form of a Line Equation

Here you will learn intercept form of a line equation i.e. intercept cut by line on x-axis and y-axis with examples. Let’s begin –  Intercept Form of a Line The equation of a line which cuts off intercepts a and b respectively from the x and y-axes is $$x\over a$$ + $$y\over b$$ = 1. …

## Two Point Form of a Line Equation

Here you will learn two point form of a line equation with proof and examples. Let’s begin – Two Point Form of a Line The equation of a line passing through two points $$(x_1, y_1)$$ and $$(x_2, y_2)$$ is  $$y – y_1$$ = ($$y_2 – y_1\over x_2 – x_1$$)($$x_2 – x_1$$) Proof :  Let m …

## Distance of a Point from a Line – Formula and Example

Here you will learn formula to find the distance of a point from a line with examples. Let’s begin – Distance of a Point from a Line The length of the perpendicular from a point $$(x_1, y_1)$$ to a line ax + by + c = 0 is |$$ax_1 + by_1 + c\over {\sqrt{a^2+b^2}}$$|. It …