Question

Please explain how you got answer

Answer 1

The angle formed by the intersection of tangent and secant outside the circle equals half the difference of the intercepted arcs.
$\frac{(18x-6)-(5x+17)}{2}=60 \\ 18x-6-5x-17=60*2 \\ 13x-23=120 \\ 13x=120+23 \\ 13x=143\\ x=143/13 \\ x=11$

Arc KNL = 18x-6 + 5x+17 
              = 23x + 11
              = 23*11 + 11
              = 264°  ← answer