2D shapes
 polygons: quadrilaterals, square, rectangle, triangle, parallelogram, rhombus, trapezoid (at least one pair of parallel lines), trapezoid (exactly one pair of parallel lines), regular
 triangles: acute, obtuse, right, isosceles, equilateral
 circles
3D shapes
 prisms, cylinders, pyramids, cones, right, oblique/skewed, sphere
 Platonic solids: tetrahedron, cube, octahedron, dodecahedron, icosahedron (all faces are regular!)



Measurement
 units imply measurement object
 angles: angles in triangle sum to 180 degrees, angles in a line sum to 180 degrees, sum of interior angles of an ngon is (n2)*180
 sum of exterior angles of a convex polygon is 360 degrees
 length: perimeter/circumference, Pythagorean theorem
 area: unit square, rectangle, parallelogram, triangle, trapezoid, circle, regular polygons
 surface area: nets, prisms, pyramids, cylinders, cones, spheres
 volume: unit cube, prism, cylinders, pyramid, cone, sphere
 how are formulas related to each other
