Help plz plz plz plz

Abouncy ball is dropped such that the height of its first bounce is 5.5 feet and each successive bounce is 64% of the previous bounce's height. what would be the height of the 7th bounce of the ball? round to the nearest tenth (if necessary).

How do you find the circumfrance of a circle?

In trapezoid abcd, ac is a diagonal and ∠abc≅∠acd. find ac if the lengths of the bases bc and ad are 12m and 27m respectively.