I have a plot of land that is .33ac. Its shape is a perfect triangle. I would like to know the outside footage measurements of it.

It depends on what you mean by 'perfect triangle'...

Take a look at some common ones and their names:

Triangle - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Triangle#Types_of_triangles)

It is a Right triangle

By a right triangle, I would suppose it's just the triangle that you would get by cutting a square into two equal parts along the diagonal?

(I'm not sure what you mean by outside footage. I'll guess that it's the length of all the three sides combined. If not, let me know)

If so, you can find it using the following formulae.

The area of the triangle is given by half the product of the two shorter sides.

And I'm using the conversion:
1 acre = 43 560 square foot

So, we get:

\frac12 (side)(side) = 0.33(43560)

This gives one side as about 170 ft (170.41127)

The longer side is then obtained using Pythagoras' Theorem...

Long\ side = \sqrt{2\times170^2} = 240.99793

The sides have length 170 ft, 170 ft and 241 ft. Add them to get the outside footage