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 •Same plane•Do not cross

PERPENDICULAR •Same plane•Cross at a 90°

angle

INTERSECTING •Same plane•Cross

SKEW •Different planes•Do not cross

PLANES CAN BE…

PARALLEL •Do not cross

PERPENDICULAR •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 or