Warm-ups P. 869 1-5 no calculators These problems are due in 3 min.

Date Sec 1-1 Concept: Identify Points, Lines and Planes Objectives: Given basic concepts in Geometry, name and sketch geometric figures

3-Undefined Terms in Geometry Point Line Plane

A Point It has no dimension. It is usually represented by a small dot Undefined. A Label with Capital Letters

Line Extends in one dimension. Usually represented by a straight line with arrows on the ends. Undefined A B l Labels: AB BA l

Plane: undefined Extends in two dimensions. Usually represented by a shape that looks like a table top. A B C M Plane M or plane ABC

Key Terms – you probably already know some of these… Coplanar and Noncoplanar Collinear and Noncollinear Ray Segment Opposite ray Intersect

Collinear: points that lie on the same line P I G S Points P, I, G, and S are collinear

Non-Collinear: Points that do not lie on the same line O G D Points D, O and G are noncollinear

Coplanar: Points that lie in the same plane G M A S H T Points M, A, T, H, S are coplanar

Non -Coplanar: Points that do not lie in the same plane G A M S H T Points G, S and H are non- coplanar

Line Segment: Part of a line that consists of 2 endpoints A B AB or BA

Ray: Part of a line that consists of a point called the initial point and all points on the line that extend in one direction. A B A is the initial point AB

Opposite Rays: If C is between A and B, then CA and CB are opposite rays B C A

Intersect: To have one or more points in common Intersection: The set of points that two or more geometric figures have in common

Example 1: L C N M P O 1. Name 3 coplanar points 2. Name 3 collinear points 3. Name 3 non-collinear points 4. Name a line segment in two different ways 5. Name a ray

Example 1: Cont. L C N M P O 6. Name a line in 2 ways 7. Name a point 8. Name the plane in two ways 9. What is the intersection of LO and plane C

Example 2: Sketch the figure described A. A line and a plane that do not intersect

B. 2 planes that do not intersect and a line that intersects each plane in 1 point

Example 3: Determine if the point lies on the line A. Y = x-4 A(5,1) 1 = 5-4 1=1 YES, it lies on the line B. Y = 2x + 3 A(7, 16) 16 = 2(7) + 3 16 ≠ 17 NO, It doesn’t lie on the line

Example 4: Graph the inequality on the number line Example 4: Graph the inequality on the number line. Tell whether the graph is a segment, a ray or rays, a point or a line X>2 or x<5 2 5 Line

Example 5: What kind of Geometric Intersection does the photograph suggest? The intersection of 2 lines The intersection of a line and a plane

Today’s Work: In Class: Homework: