Tag
Geometry
Entries tagged geometry.
4 entries
Congruence and similarity
Two figures are congruent when one can be placed exactly on the other by moving it without stretching, and similar when one is an exact scaled copy of the other, same shape, possibly different size.
7 min
ConceptPoints, lines, angles, and planes
Geometry builds everything, triangles, circles, solids, from a small set of undefined primitives, point, line, and plane, plus a short list of relations, incidence, betweenness, and angle, that constrain how those primitives can meet.
7 min
ConceptThe Pythagorean relationship
In any right triangle, the area of the square on the hypotenuse always equals the combined area of the squares on the other two sides, a fact provable by rearranging area rather than by measuring it.
7 min
ConceptVectors as directed quantities
A vector is a quantity that has both a magnitude and a direction, and that combines with others by placing them tip to tail rather than by ordinary addition of numbers.
7 min