Answer:
18cm
Step-by-step explanation:
[tex]area \: of \: rhombus = \frac{1}{2} \times \: d1 \times d2 \\ 216 = \frac{1}{2} \times 24 \times d2 \\ d2 = \frac{216 \times 2}{24} \\ = 18cm[/tex]
