Tolong banget plisssss

L = (1/2) * AB * CD
72 = (1/2) * AB * 12
AB = 12
AD = (3/4) * AB = 9
(AC)^2 = (AD)^2 + (CD)^2
(AC)^2 = (9)^2 + (12)^2
(AC)^2 = 225
AC = 15
jawabannya D