Answer:
3x+6 is inverse of 3x-6.it is a additive inverse and if we add both we get 0.
Area of a triangle is,

Substitute the numbers,


The above number is the base.
Using the pythagorean method let's calculate for "c" the hypotenuse.

Substitute

Solve,

Simplify,

Calculate one last time,

The hypotenuse is 37 inches.
I dont think this may be right but i think it is 401