draw a triangle

[Kocoo]

Hello...

for a school project, i have to make a program that draws a triangle..
as input you insert the lenght of a,b and c sides..

I don't know how to get the final point C..

I have A(0,0), B(c,0), but can't find out point C.

i'm using SFML to display the triangle..

Any help on how to get the point C?

[hamsterman]

This may not be the most straight way, but I don't see anything else right now.
First calculate the area of your triangle using http://en.wikipedia.org/wiki/Heron's_formula
Then from area you can calculate height of your triangle h, which is the y coordinate of C.
Then, when you have h, you can find the x coordinate using http://en.wikipedia.org/wiki/Pythagorean_theorem

[Kocoo]

Ok, thx a lot..

Can you just write me the formula for x? having problems with it :)

[hamsterman]

p = (a+b+c)/2;
S = sqrt( p * (p-a) * (p-b) * (p-c) );
S = c*h/2, so h = 2*S/c.

[Kocoo]

that's for the y coordinate right?

[hamsterman]

Oh. sorry.
when you have y, since point A is at the origin and line AC is named b here,
x*x+y*y = b*b;
, so
x = sqrt( b*b-y*y );