Need a formula for aria of triangles.?

Have a water flow problem that involves triangle shaped openings through which

the water flows. But the triangles are different types and I need to be able to

cause them to be equal by knowing how to get the aria of either. Both have

one right angle but on one the sides are different lengths and on the other

the lags are going to be equal lengths. An example of the problem (actually

one half of the actual problem) is: First triangle has one unknown length but

the other two sides are 1" X 3". The other length seems to be 3 5/32".

That is three and five thirty seconds inches.

So what I need to know is how long do the legs need to be if they are both the

same length...if the aria of both triangles are to be equal.

Could it possibly be as simple as if one is 3 x 1 then the other must be

1.5 x 1.5 in order for them both to be of equal aria ?

As if that isn't confusing enough I'll tell you that I'm dividing a 1"x3" rectangle

in half and trying to get a triangle that has that much aria. This would be

the triangle which has equal length legs coming from the right angle.