This chapter is concerned with an important question in geometry: the division (or dissection) of 2D figures. This question has been represented and developed in numerous mathematical traditions since Mesopotamian times. In particular, the great geometers of ancient Greece such as Euclid or Hero of Alexandria each tackled it in their own way. Many other developments were achieved in Islamic countries both in the East and West. Based on extracts from medieval Latin literature of the twelfth and thirteenth centuries with Plato of Tivoli, Fibonacci and Jordanus de Nemore, this chapter deals with just one basic geometric problem: ‘dividing a triangle into two equal parts’, from which the geometric constraints evolve. A broad historic introduction allows these problems to be placed in context; it is a great opportunity to introduce an historic perspective into mathematics teaching. When an author is quoted for the first time, their name is followed, in brackets, by the date of death when known or the proven period when they were active. When too little viable information is known, only the century will be given.