The angles of a quadrilateral sum to 360 degrees. A pentagon's exterior angles are 108 degrees. A hexagon's exterior angles are 60 degrees. So, <BAL AND <KLA are 60+108 or 168. 168 + 168 = 336. 360-336 = 24. If you write m<ABK as x, you can write the sum of <ABK and <LKB as 2x. If 2x=24, x=12. So, m<ABK is 12 degrees.
