Big Idea – We can describe, measure, and compare spatial relationships. to build on students' knowledge of triangle and to develop students' reasoning with properties of triangle to develop students' ...

The ancient Greek geometer Euclid presented a list of five axioms he held to be self-evidently true. They are (or are equivalent to): You can draw a line between any two points. You can extend lines ...

Earlier today I set you these mind-mangling puzzles about non-Euclidean geometry, in which the internal angles of triangles do not add up to 180 degrees. 1. Right, Right, Right. Assume the Earth is a ...