Please help?
Find measure of angle C

Ill mark the brainliest if you me with the these three questions 7,8,9

Liz is shipping a package to her friend. the maximum weight of a medium flat-rate box is 20 pounds, including the box which weighs 6 ounces. write and solve an inequality to describe the possible weight in pounds, w, of the contents that liz will ship to her friend if she must use a medium flat-rate box. use the drop-down menus to explain your answer.

Collin did the work to see if 10 is a solution to the equation r/4=2.4