CM of triangle with integration

[drugcpp]

Homework Statement

I need to calculate center of mass of this isosceles triangle using integration:

the density is constant.

Homework Equations

R_cm = integral(xdm) / integral(dm)

The Attempt at a Solution

I know how to begin:
dm = density * dx * dy;
x = double-integral(x*dx*dy) / integral(dy*dx);
y = double-integral(y*dx*dy) / integral(dy*dx);

I have problem with defining the boundaries of integration.
let's say that c is the base and b is the height of this triangle.
I think that -c/2 to c/2 are the boundaries for x, but I have no idea what the boundaries for y are. I know how to solve similar problem with right triangle, a boundary for y there is defined by function b-(b/a)x. Any help?

 

[ehild]

The triangle is made of two right triangles.

ehild

 

[drugcpp]

Really?! OMG!
I see that myself. What I asked is integration limit. I've solved it myself already, the limit is simply b.