1. Lesson 01 – Points, Lines, & Planes
Identify and model points, lines, and planes.
Identify intersecting lines and planes
Unit 01 – Introduction to Logic & Euclidean Geometry

2. Undefined Terms
In geometry, point, line, and plane are considered undefined terms because they are only explained using examples and descriptions.

5. Name the points, Lines, & Planes

6. Collinear points are points that lie on the same line.
Coplanar points are points that lie in the same plane.

8. Lines can be…. PARALLEL PERPENDICULAR INTERSECTING SKEW Same plane
Do not cross
PERPENDICULAR
Cross at a 90° angle
INTERSECTING
Cross
SKEW
Different planes

9. Planes can be… Parallel Perpendicular intersecting Do not cross
Cross at a 90° angle
intersecting
Cross at a non 90° angle

10. intersections
Lines intersect at a POINT.
Planes intersect at a LINE.

11. Defined Terms
Terms that can be defined using known words such as point or line are called defined terms.

12. Practice Draw and label a figure for the following situation:
Plane R contains AB and DE, which intersect at point P.
Add point C on plane R so that it is non collinear to 𝑨𝑩 or 𝑫𝑬 .