Need Help with my App

A little stuck need help on how to do this below and this is also what i have so far

See my website:

You can do this by making a list of the squares of the sides.
The list will have 3 numbers in it.
Pick the largest number from the list, by looping through the list.
Also, take the sum of the list.
If the largest square exceeds half the sum, it is an obtuse triangle.
If the largest square exactly equals half the sum, it is a right triangle.
Otherwise, it is an acute triangle.

In your 'If' logic, it already tests to see if length 1 equals lengths 2 and 3, so there is no need to also test if the text box is empty.

I suggest you present your Users with diagrams of the triangles as Image Buttons, so that they can select. Via the button click you call the relevant procedure or perform the math in the Button Click event Block.