1. Line Segments
1.1. is a part of a line that is bounded by two distinct end points
1.2. https://www.splashmath.com/math-vocabulary/geometry/line-segment
2. Shapes
2.1. The form of an object - how it is laid out in space (not what it is made of, or where it is).
2.1.1. 2D
2.1.1.1. https://www.mathsisfun.com/shape.html
2.1.1.2. Circles
2.1.1.3. Triangles
2.1.1.4. Quadrilaterals
2.1.2. 3D
2.1.2.1. http://www.coolmath4kids.com/polyhedra/index.html
2.1.2.2. Spheres
2.1.2.3. Cubes
2.1.2.4. Pyramids
2.1.2.5. Cylinders
2.1.2.6. Prisms
2.2. http://www.kidsmathgamesonline.com/pictures/shapes.html
3. Lines
3.1. https://www.mathsisfun.com/geometry/dimensions.html
3.2. is a straight one-dimensional figure having no thickness and extending infinitely in both directions.
3.2.1. Parallel
3.2.2. Perpendicular
3.2.3. Straight
3.3. https://www.mathsisfun.com/geometry/dimensions.html
4. Points
4.1. A precise location or place on a plane. Usually represented by a dot.
4.2. http://www.basic-mathematics.com/basic-geometry.html
5. Angles
5.1. The amount of turn between two straight lines that have a common end point (the vertex).
5.1.1. Acute
5.1.1.1. an angle that is less than 90°
5.1.2. Right
5.1.2.1. an angle that is 90° exactly
5.1.3. Obtuse
5.1.3.1. an angle that is greater than 90° but less than 180°
5.1.4. Straight
5.1.4.1. an angle that is 180° exactly
5.1.5. Reflex
5.1.5.1. an angle that is greater than 180°
5.1.6. Circle
5.1.6.1. an angle that equals 360°
5.2. https://www.brainpop.com/math/geometryandmeasurement/angles/
6. Rays
6.1. A line with a start point but no end point (it goes to infinity)
6.2. http://www.mathopenref.com/ray.html
7. Symmetry
7.1. https://www.youtube.com/watch?v=PBW1dyOwUbA
7.2. Symmetry is when one shape becomes exactly like another if you flip, slide or turn it.
7.2.1. Reflection
7.2.2. Mirror
7.2.3. Rotational
7.2.4. Point
8. http://www.the-best-childrens-books.org/geometry-shapes.html
9. Geometry
9.1. http://www.learninggamesforkids.com/4th-grade-math/geometry-terms-4th.html
9.2. http://www.math-salamanders.com/4th-grade-geometry.html
10. Draw and identify lines and angles, and classify shapes by properties of their lines and angles.
10.1. CCSS.MATH.CONTENT.4.G.A.1
10.1.1. Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
10.2. CCSS.MATH.CONTENT.4.G.A.2
10.2.1. Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category, and identify right triangles.
10.3. CCSS.MATH.CONTENT.4.G.A.3
10.3.1. Recognize a line of symmetry for a two-dimensional figure as a line across the figure such that the figure can be folded along the line into matching parts. Identify line-symmetric figures and draw lines of symmetry.