Patrick B. answered 07/06/19
Math and computer tutor/teacher
Right triangle ABC,,,,
C is the right angle,
B on the bottom, C directly above B and A on the right
b = AC = 2
A = inverse_tangent(5/12) = 22.619....
cos A = b/c = 2/c
c = 2/ cos A = 2 / cos 22.619... = 13/6
sin A = a/c = 6a/13
a = 13* sin A / 6 = 13 * sin 22.619.../6 = 5/6
Note that tan A = 5/6 divided by 2 = 5/12 as given