Having high school students prove geometrical propositions became the norm in the United States with the reforms of the 1890's - when geometry was designated as the place for students to learn the ...

https://doi.org/10.4169/amer.math.monthly.118.03.229 • https://www.jstor.org/stable/10.4169/amer.math.monthly.118.03.229 Copy URL Abstract We give a natural and ...