Answer:
C) x = 20.8
Explanation:
Since the line with the length equal to 6 forms a right angle on line x then we know it is perpendicular and bisects it.
Plug in the values: a^2 + b^2 = c^2
a^2 + 6^2 = 12^2
a^2 + 36 = 144
a^2 + 36 - 36 = 144 - 36
a^2 = 108
√a^2 = √108
a = √108
a = 10.3923048454
a = 1/2 x
2a = x
2(10.3923048454) = x
x = 20.7846096908
x = 20.8