Question

Why was limestone used to build pyramids?

Answer 1

Most of the material used was fairly rough, low grade limestone used to build the pyramid core, while fine whitelimestone was often employed for the outer casing as well as to cover interior walls, though pink granite was also often used on inner walls

Answer 2

limestone is a sedimentary rock and according to Geographical feature of Egypt the sand and blowing wind will superimpose the particle more on this rock hence this type of rock was used