Answer:
14.4
Step-by-step explanation:
sin x = 24/30
x = sin^-1 (24/30) = 53.13
sin 53.13 = x/18
x = sin 53.13 x 18 = 14.4
The second condition tells you that

is half the size of

, so

, which could be rewritten in several ways. In standard form, that would be

.
Answer: what rectangle???