Using the Pythagorean theorem:
x^2 + (x-2)^2 = (√20)^2
Simplify the right side:
x^2 + (x-2)^2 = 20
Subtract 20 from both sides:
x^2 + (x-2)^2 - 20 = 0
Factor:
(x-4)(x+2) = 0
Solve for each x:
x = 4 and x = -2
The side cant be a negative value, so the answer would be x = 4
The answer is B.