
Why?
We have the isosceles right triangle. The length of legs are 6. Use the Pythagorean theorem:

In general, the formula for calculating the hypotenuse in an isosceles right triangle is 
a - a leg, h - a hypotenuse
<span>7^2•3^2+(1+2)^0•3-4^2•1
= 49</span>•9 + 1•3 - 16<span>•1
= 441 + 3 - 16
= 428</span>
Answer:
if I'm not wrong I think it's B
If they proportional, it implies
(x+2)/(x-1) = 8/10
Or 10x +20 = 8x-8
Or 2x = -28 or x = -14