Answer:
26/15
Step-by-step explanation:
See attached image.
Suppose we let
, so that
.
Also, recall the double angle identity for cosine:

So, we can rewrite and compute the integral using the substitution, as





I'm not sure about the answer, but this is how I would do it, since 15% and $150 are the same based on the question. do let me know if it's right! :)
The permimiter of a is 18 and the area is 9