A basic intro the helps you to understand the definition of a sector (of a circle)
Stinky Kid Math
Stinky Kid Math has been developed to help students of all ages to build a solid mathematical foundation in pre-algebra, algebra, and geometry. The understanding of these concepts becomes the foundation for all math that comes afterwards, and a lack of this knowledge is often the reason people struggle in upper-level math classes. Stinky Kid Math brings math to life by making concepts relatable to creative, right-brained learners, and it makes it fun!