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

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

Name the points, Lines, & Planes

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

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

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

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

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

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 .