Answer:
AD = 10
Step-by-step explanation:
Find AE.
AE = (AB - DC) / 2
AE = (24 - 12) / 2
AE = 12 / 2
AE = 6
Pythagorean theorem
a² + b² = c²
AE² + DE² = AD²
6² + 8² = AD²
36 + 64 = AD²
100 = AD²
√100 = AD
10 = AD
