The word form of 0.3 is what

What is the nth term rule of the linear sequence below? 27 , 25 , 23 , 21 , 19 , . .

Two streets intersect at a 30- degree angle. at the intersection, the are four crosswalks formed that are the same length. what type of quadrilateral is formed by the crosswalks?

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