Geometry Basics
We’ve included this first little review of geometry
basics because you need to understand certain terms and ideas before
you can discuss the geometry topics tested on the SAT.
Points
A point is a way to describe a specific location in space.
Below is pictured the point B.
A point has no length or width. Though in the picture
point B is a black dot, in real life, points
take up no space and are not tangible. Points are useful for identifying
specific locations but are not objects in themselves. They only
appear so when drawn on a page.
Lines
A line is an infinite set of points arrayed in a straight
formation, named by any two points in that set. A line has no thickness
but is infinitely long in both directions. To form a line, take
any two points, A and B,
and draw a straight line through them. The resulting line is a called
line AB.
A line can be drawn through any two points.
Line Segments
A line segment is the portion of a line that lies between
two points on that line—in this example, points A and B.
Whereas a line has infinite length, a line segment has a finite length.
A line segment is named by the two points it lies between
A line segment can be drawn between any two points.
Rays
A ray is a cross between a line and a line segment. It
extends without bound in one direction but not the other. Below
is a figure of a ray:
A ray is named by its endpoint and another point that
it passes through.
Okay, now we’ve covered the basics. All of the following
topics are tested directly by the SAT.
