Using vectors to find the volume of a pyramid

Hi,

So here's my problem (Shake):

The equation of a plane is 3x+2y-6z=12

Which meets the x,y,and z-axis at points A, B, and C, which I calculated to be (4,0,0), (0,6,0), and (0,0,-2) respectively (I think I'm correct).

Now I have to find the volume of the pyramid OABC. I'm guessing it's a triangle based pyramid with the peak at O (origin). I already found the area of the base to be 14 using the fact that A=1/2*magnitude(AC x AB).

Now I'm stuck on how to find the height of the pyramid?

EDIT: Or actually what just came to mind is the fact that the plane is 12 units from the origin can I use that fact as the height? (might have just solved it /facepalm/)

Any help will be appreciated. Thanks.