POINTS, LINES AND PLANES Section 1-1 Jim Smith JCHS
What is Geometry? • Geometry is the study of shapes • They studied Geometry in Ancient Mesopotamia & Ancient Egypt • Geometry is important in the art and construction fields
POINT A POINT is an exact location on a graph, shape or in space. The ball is a POINT on the line.
LINE A LINE goes in opposite directions and never, ever ends. Take a pearl necklace and stretch it out. The pearls are like points on a line.
PLANE A PLANE is a flat surface that goes on forever in all directions. Imagine sitting on an island in the middle of the ocean. No matter which way you look…all you see is water…forever.
T p S R TO NAME A LINE- USE ANY 2 POINTS ON THE LINE LINE RT or LINE ST or LINE RS Or a single italicized or cursive letter. RT RS
POINTS ON THE SAME LINE ARE CALLED COLLINEARPOINTS A, B, AND Y ARE COLLINEAR . . Y . B A
TO NAME A PLANE WE USE 3 OR 4 NONCOLLINEAR POINTS PLANE WAG or XAG or WXA . .A Q X .W .G PLANES CAN BE NAMED USING 1 LETTER …. PLANE Q
THE INTERSECTION OF 2 LINES IS A POINT s S IS THE INTERSECTION OF THE 2 LINES
LINE XY INTERSECTS PLANE Q AT POINT X Y *Notice that the plane is named with a single cursive or italicized letter Q . X
THE ARROW INTERSECTS THE TARGET AT 1 POINT
Lines YB and XZ do not intersect Z . Y . B X These are SKEW. They do not intersect because they are not in the same plalne!
THE INTERSECTION OF 2 PLANES IS A LINE A D G B C E E G H C F
POINTS AND LINES CONTAINED IN THE SAME PLANE ARE CALLED COPLANAR Y G. P S. W. X