if y =8' and z=the square root of 73 what is the length of x
Assuming z is the hypotenuse of a right triangle and not the 3rd dimension,
z = sqrt(73) = sqrt(x^2 + 8^2)
x^2 + 8^2 = 73
x^2 = 73 - 64 = 9
|x| = 3 is the length of x.
If x has direction it could be ±3.