What is the answer?

In the proof of the triangle angle sum theorem, you must draw an auxiliary line. which construction must you use to draw this line?

Recall that the owner of a local health food store recently started a new ad campaign to attract more business and wants to know if average daily sales have increased. historically average daily sales were approximately $2,700. the upper bound of the 95% range of likely sample means for this one-sided test is approximately $2,843.44. if the owner took a random sample of forty-five days and found that daily average sales were now $2,984, what can she conclude at the 95% confidence level?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.