Find the length of side CA

Ican figure out 20 shares multiply by $117.98 =2359.6920 shares multiply by $124.32=2486.40then take 40 shares multiply by $128.48=5139.20after that i'm lost any be greatly appreciated.

We have enough material to build a fence around a station that has a perimeter of 180 feet the width of the rectangular space must be 3 1/4 feet what must the length be

Suppose a pendulum is l meters long. the time,t,in seconds that it tales to swing back and forth once is given by t=2.01