Answer:
18p? I don't know what other expressions could be equivalent. I just added 9p to 9p to get my answer.
<em>The answer is 25.12 exactly</em>
In this question, it is given that An inverse trigonometric function is used to find the value of an unknown obtuse angle in a triangle. The inverse function returns the angle 68°.
Since the angle is obtuse angle, it means the measurement of the angle is greater then 90 degree. And to find the angle measurement, we have to subtract the given angle from 180 degree.
So the unknown angle is

And that's the required answer .
Cindy needs to buy 8 packs of invitations.