Please explain step by step, thank you

Suppose a ball is dropped fromca height of 6ft. it bounces back up but time it bounces, it reaches only 7/10 of its pervious height. what is the total of each height that the ball reaches after 5 bounces

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

Parallelogram rstu is a rhombus. m∠r = 120° what is m∠t = 120 (what is m∠rsu? )