# What is the perimeter of a triangle with corners at (1 ,4 ), (5 , 2 ), and (9 ,7 )?

##### 1 Answer
Aug 7, 2016

$= 19.4$

#### Explanation:

So sides of the triangle with corners at $\left(1 , 4\right) , \left(5 , 2\right) , \mathmr{and} \left(9 , 7\right)$ are as follows
Side $1$
$\sqrt{{\left(5 - 1\right)}^{2} + {\left(4 - 2\right)}^{2}}$
=sqrt(4^2+2^2
$= \sqrt{16 + 4}$
$= \sqrt{20}$
$= 4.5$
Side $2$
=sqrt((9-5)^2+(7-2)^2
=sqrt(4^2+5^2
$= \sqrt{16 + 25}$
$= \sqrt{41}$
$= 6.4$
Side $3$
$\sqrt{{\left(9 - 1\right)}^{2} + {\left(7 - 4\right)}^{2}}$
=sqrt(8^2+3^2
$= \sqrt{64 + 9}$
$= \sqrt{73}$
$= 8.5$
So perimeter $= 4.5 + 6.4 + 8.5 = 19.4$