Materials were written for an entire year's course in geometry in which transformations were used to develop the concepts of congruence, similarity, and symmetry, as well as being a vehicle for proof.

FRANK M. ECCLES, TRANSFORMATIONS IN HIGH SCHOOL GEOMETRY, The Mathematics Teacher, Vol. 65, No. 2 (FEBRUARY 1972), pp. 103, 165-169 ...

What’s math got to do with it? Everything, says Dan Meyer, creator of the the popular blog dy/dan. Meyer is one of America’s most popular math educators—he has 43,400 followers on Twitter who are ...