Thread: Perimeter of a Triangle using Cartesian coordinates

1. Perimeter of a Triangle using Cartesian coordinates

Hi: I am trying to solve finding the equation of an Incenter of a triangle and the InRadius. I am stuck on the idea of finding the side lengths if I am using a Cartesian coordinate system, the triangle is either acute or scalene . Any help is appreciated! 2. Re: Perimeter of a Triangle using Cartesian coordinates

If the problem is "find the perimeter" just find the lengths of the three sides and add them! The distance from $\displaystyle (x_0, y_0)$ to $\displaystyle (x_1, y_1)$ is $\displaystyle \sqrt{(x_1- x_0)^2+ (y_1- y_0)^2}$. You are given the coordinates of the three points. Find those three distances and add.

3. Re: Perimeter of a Triangle using Cartesian coordinates Originally Posted by pbayer Hi: I am trying to solve finding the equation of an Incenter of a triangle and the InRadius. I am stuck on the idea of finding the side lengths if I am using a Cartesian coordinate system...
You are trying to find the Incenter and Inradius,
and don't know how to find side lengths?
That's a bit like trying to cook and not knowing how to turn on the stove Also, your diagram is faulty (if in 1st quadrant as the coordinates suggest).

I suggest the following:
1: change your labelling from 1,2,3 to A,B,C respectively
2: get some graph paper and plot your triangle correctly
3: come back with a new/correct diagram
4: show your work

4. Re: Perimeter of a Triangle using Cartesian coordinates

Thanks for the equation, I programmed it into C++ and it worked great!

Unfortunately I suffered a traumatic brain injury from an autoimmune disease so my logic is often faulty .