GEOMETRY HELP?!??! homework?

1. Pythagorean theorem A^2+B^2=C^2 in which C is the hypotenuse of a right triangle. the same thing will help for the rectangle- think of the sides as the sides of a right triangle and the diagonal as a hypotenuse. The Pythagorean theorem will work with the square also. for the isoceles triangle....think of 8 as being one leg and 10 as being the hypotenuse. and split it into two right triangles...this might sound confusing but...it's hard to explain over the internet >_<