Answer with step-by-step explanation:
If AD = DB, then D would be the midpoint of AB. If AB = BC, then B would be the midpoint of AC. If so, lets add another point called E. E is the midpoint of BC, which would divide AC into fourths. DC = DB + BE + EC. So, DC is 3/4 of 24, which is 18.
Hope this was helpful!
