Lesson 1: 1-1 Points/Lines/Planes

What is a point?
What is a line?
What is a plane?
What is space?

Undefined Term
Point
Line
Plane
Collinear
Coplanar
Intersection
Definition
Defined term
Space

G.CO.1: Know precise definitions of angle, circle, perpendicular line, parallel line, and line segment; based on the undefined notions of point, line, distance along a line, and distance around a circular arc.

A point is a location without shape or size. A line contains points and has no thickness or width. A plane is a flat surface that has no depth and extends infinitely in all directions. These terms can be used to build definitions of new concepts.

Example: On a subway map, the locations of stops are represented by points. The route the train can take is modeled by a series of connected paths that look like lines. The flat surface of the map on which these points and lines lie is representative of a plane.

Students approaching grade level can be given practice problems in small groups to work with other students or directly with the teacher.
Students beyond grade level can make deeper connections in the following way: Explain how points, lines, and planes exist in nature. For example, planes can model leaves, lily pads, and the surface of a pond; lines can model spiderwebs, sunbeams, tree trunks, the edfe of a riverbed, and the veins of a leaf.

Formative Assessment

Textbook in class

Access online textbook and resources through class link.