Will give brainliest ! the angle addition postulate is sometimes described as "the whole is equal to the sum of its parts." explain how this description applies to the angle addition postulate.

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 ,w, of the contents that liz will ship to her friend if she must use a medium flat-rate box.