If you are interested in exploring knowledge questions linking maths and art, you might consider this clip of film which suggests that the golden ratio in maths is the code behind celebrity face shapes that are considered to be beautiful. Useful for considering the idea that beauty is not just in the eye of the beholder.
The following Dove advert (link below) reveals how many pictures we see in advertisements are actually the product of clever make-up and photoshop. This is well worth watching if you want to consider the cultural dimensions of beauty. You might consider how else we might think of beauty and what different factors shape our notion of beauty. It may be worth thinking about how this is similar or different to other related examples such as the factors that shape our notion of intelligence.