1.4 Sketching Intersections Goal: Sketch simple figures and their intersections.

Activity Where do AB and CD meet? Where do AB and EF meet? When the cards are together, where to CD and EF meet? Where to planes M and N meet? Are CD and EF coplanar? Explain.

Activity Where do EF and UV meet? Where do planes M and P meet? Do planes N and P meet?

Key Words Intersect Intersection Figures intersect if they have any points in common. Intersection The point or points that the figures have in common.

Intersection of Two Lines Postulate 3 Intersection of Two Lines If two lines intersect, then their intersection is a point.

Intersection of Two Planes Postulate 4 Intersection of Two Planes If two planes intersect, then their intersection is a line.

Name Intersections of Lines Use the diagram to do the following: Name the intersection of PS and QR. Name the intersection of TV and QU. Name the intersection of PS and UV. Point R Point U They do not intersect

Name Intersections of Planes Use the diagram to do the following: Name the intersection of planes X and Y. Name the intersection of planes Y and Z. Name the intersection of planes Z and X. Line p Line q They do not intersect

Sketch Intersections of Lines and Planes Sketch a plane. Then sketch the following: A line that is the plane A line that does not intersect the plane A line that intersects the plane at a point

Sketch Intersections of Planes Sketch two planes that intersect at a line.

Homework 1.4 pgs. 25-27 10-32 ALL