This is probably a joke but I'll answer anyway
By 'cheeks' they mean buttocks so by "making them clap" is referring to them being so big/thick that they clap or make noise when you walk or move around or something.
I probably got played lol but whatever
Answer:
The amount of blue is always the last two digits in the hex code- in this case, c9!
In photography, composition is the way of how elements are arranged to create the best shot. A good composition contributes to a nice photography. One example is street photography. In the streets, you can't control objects based on how you want them to be positioned. Instead, you anticipate for the objects to move in the exact spot on where you wanted them to be.