Explanation:
remember : the sum of all angles in a triangle is always 180 degrees.
the law of sines :
a/sin(A) = b/sin(B) = c/sin(C) with the sides being always opposite of the angles.
so,
the opposite angle of x is
180 - 90 - 58 = 32 degrees.
x/sin(32) = 11/sin(58)
x = 11×sin(32)/sin(58) = 6.873562871...
rounded x = 6.9