GeoGebra Activity 1: Points, Lines, and Planes
In order to start our journey into Geometry, we first have to understand the meaning of some key terms.
Part 1
1. Move points E, F, and G so they are coplanar (lie on plane A). Planes are determined by three points, lines are determined by 2 points, and points are determined by 1 point. Plane A has dotted "edges" because it extends infinitely in all directions! Think of a plane as a floor that extends infinitely.
2. Move point H so it lies outside of plane A.
3. Move the line so it contains point H and intersects the plane at point F. Points H and F are collinear because they lie on the same line ().
3. Move the line segment to create line segment .
4. Move the ray to create ray .
NOTE: You can zoom in and out by clicking on the rightmost tool (the one made of perpendicular lines).
Part 2: Intersections between two lines
Take a few minutes to mess around with the toolbar below. Create a point, draw a line, make a triangle, draw a picture! Have a little fun! Then answer the following question: There are three cases of relationships between two lines. What are they? Show one case using the toolbox below! Remember that a line is determined by two points, so start by adding two points before drawing a line between them.
Part 3: Intersections of a plane with a line
1. In the image below, where does line intersect plane P?
Part 4: Intersecting Planes
1. Where does plane A intersect with plane B?
2. There are two other cases of relationships between two planes. What are they? [Hint: Think about two pieces of paper with "edges" that extend infinitely in all four directions of the paper.]