Without using formula, show that points $( -2,\ -1),\ ( 4,\ 0),\ ( 3,\ 3)$ and $( -3,\ 2)$ are the vertices of a parallelogram.


Given: Points $( -2,\ -1),\ ( 4,\ 0),\ ( 3,\ 3)$ and $( -3,\ 2)$

To do: To show that the given points are the vertices of a parallelogram without using the formula.

Solution:

Let points $( -2,\ -1),\ ( 4,\ 0),\ ( 3,\ 3)$ and $( -3,\ 2)$ be respectively denoted by $A,\ B,\ C$ and $D$.

Now, Slope of $AB=\frac{0-( -1)}{4-( -2)}=\frac{0+1}{4+2}=\frac{1}{6}$

Slope of $CD=\frac{2-3}{-3-3}=\frac{-1}{-6}=\frac{1}{6}$

 

$\Rightarrow$ Slope of $AB=$Slope of $CD$

$\Rightarrow\ AB$ and $CD$ are parallel to each other

Also, Slope of $BC=\frac{3-0}{3-4}=\frac{3}{-1}=-3$ 

Slope of $AD=\frac{2-( -1)}{-3-( -2)}=\frac{2+1}{-3+2}=-3$ 

$\Rightarrow$ Slope of $BC =$ Slope of $AD$

$\Rightarrow\ BC$ and $AD$ are parallel to each other. 

Therefore, both are pairs of opposite sides of quadrilateral $ABCD$ are parallel. 

Hence $ABCD$ is parallelogram.

Tutorialspoint
Tutorialspoint

Simply Easy Learning

Updated on: 10-Oct-2022

22 Views

Kickstart Your Career

Get certified by completing the course

Get Started
Advertisements