Hypothenus = sqrt ((x^2 - y^2)^2 + (2xy)^2) = sqrt(x^4 - 2x^2y^2 + y^4 + 4x^2y^2) = sqrt(x^4 + 2x^2y^2 + y^4) = sqrt(x^2 + y^2)^2 = x^2 + y^2
B is the only one that makes sense if you break them each down. An Acute doesnt have every Pair of angles congruent, the don't have to have proportional side lengths, and it can't have a right angle or it would be a right triangle.
69% can be written as
69/100
That cannot be reduced any further since 69 and 100 do not have any common factors other than 1
Yes, it is a linear equation.