Critical issues in the design of the school geometry curriculum

The fundamental problem in the design of the geometry component of the mathematics curriculum is simply that there is too much interesting geometry, more than can be reasonably included in the mathematics curriculum. The question that taxes curriculum designer is what to include and what to omit. This paper does not seek to resolve the disagreements over the geometry curriculum as, given the nature of the problem, such an endeavour is unlikely to be successful. Rather, the aim is to identifying and review critical issues concerning the design of the geometry curriculum. These issues include the nature of geometry, the aims of geometry teaching, how geometry is learnt, the relative merits of different approaches to geometry, and what aspects of proof and proving to accentuate.