Essential Content for Elementary Teachers
I. Develop an understanding of basic geometric concepts including: point, line, plane, space, line segment, betweeness, ray, angle, vertex, parallelism, perpendicularity, congruency, similarity, simple closed curve, Pythagorean relationship
II. Identify types of angles including acute, right, obtuse, straight, reflex, vertical, supplementary, complementary, corresponding, alternate interior, and alternate exterior
III. Recognize and define common geometric shapes
A. Two-dimensional geometric shapes
1. Triangles: be able to classify by sides (equilateral, scalene, isosceles) and classify by angle (right, acute, obtuse)
2. Quadrilaterals (trapezoid, parallelogram, rectangle, square, rhombus, kite): identify characteristics and relationships among these shapes
3. Polygons, regular polygons
4. Circle
B. Three-dimensional geometric shapes
1. Polyhedra (prisms, pyramids), regular polyhedra (Platonic solids): connecting polyhedra to polygons, nets
2. Cylinder, cone, sphere
