Unit 1.1 Defining Geometry Vocabulary Number of Instructional Days: 8 Content Standards: Congruence G-CO Experiment with transformations in the plane 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.

Standards of Mathematical Practice: Attend to Precision Look for and Make Use of Structure

Essential Questions Why did ancient civilizations pursue Geometry concepts? Why are there undefined notions of Geometry? Who is the most influential mathematician of all time?

1.1.2 Points, Lines, and Planes

Line Point A geometric figure with no dimension Indicates a specific location Named used ONE capital letter Example: A geometric figure with one dimension Extends without end in two directions Always straight; no curves Named using two capital letters (points on the line) Example:

Plane Line Segment “ a piece of a line” a geometric figure with two dimensions Extends without end in two directions (diagrams appear to have edges but there are none) Named using any three points that are on the plane Example: Plane GHJ Plane JIK Plane IJH “ a piece of a line” A geometric figure that has two endpoints and can be measured Named using the endpoints Example:

Ray Opposite Rays A geometric figure that has one endpoint and extends without end in one direction Named using endpoint listed first and another listed after Example: Two rays that have the same endpoint and continue in opposite directions Example:

Examples: Intersection POINT POINT LINE The intersection of two lines is a The intersection of a line and a plane is a The intersection of two planes is a Intersection POINT The point(s) that two geometric figures have in common POINT LINE

Examples: Find the intersection of the given figures:

Example: