Step-by-step explanation: The equation of the line AC is y = (-3/4)x + 12. The line perpendicular to AC and passing through point B is y = (4/3)x. The point of intersection between BK amd AC is (144/25, 192/25). Those are the side lengths. Use Pythagorean theorem to find the hypotenuse.
I did these about 1 year ago but i think you subtract the 6 from 30 and then divide by 4, and that gives u 24/4 which is 6. i barely barely remember some so