Download Geom ch. 1

Chapter 1
1-1 Points, Lines, and Planes
Point—a location in space
Line—made of points and has no thickness or width.
Collinear—when points are on the same line.
Plane—is a flat surface made up of points.
Coplanar—points that lie on the same plane
Point
Line
Plane
Model
Drawn
Named by:
Facts:
Words/Symbols
Space—a boundless, three dimensional set of all points. Space can contain lines and planes.
1-2 Linear Measure and Precision
Line Segment—a part of a line with endpoints. It can be measured.
Precision of any measurement depends on the smallest unit available on the measuring tool.
Betweeness of points—relationship
Congruent—when segments have the same measure
1-3 Distance and Midpoints
Distance Formula—is used to find the distance between two points on a coordinate plane.
Midpoint—the point halfway between the endpoints of a segment
Segment Bisector—any segment, line, or plane that intersects a segment at its midpoint
1-4 Angle Measure
Degree—a unit of measure used in measuring angles and arcs. An arc of a circle with a measure
of 1 degree if 1/360 of the entire circle.
Ray—a part of a line. It has one endpoint and extends indefinitely in one direction.
Opposite rays—two rays that share the same beginning point but going in opposite direction
Angle—the intersection of two noncollinear rays at a common endpoint
Sides –the rays of an angle
Vertex—the common endpoint in an angle
Interior of the angle—anything inside the rays of an angle
Exterior of the angle—anything outside the rays of an angle
Right angle—any angle that equals 90 degrees
Acute angle—an angle with a degree measure less than 90.
Obtuse Angle—an angle with degree measure greater than 90 and less than 180.
Angle Bisector—a ray that divides an angle into two congruent angles
1-5 Angle Relationships
Adjacent angles—two angles that lie in the same plane, have a common vertex and a common
side, but no common interior points
Vertical angles—two nonadjacent angles formed by two intersecting lines.
Linear Pair—a pair of adjacent angles whose non common sides are opposite rays.
Complementary Angles—two angles with measures that have a sum of 90
Supplementary Angles—two angles with measures that have a sum of 180
Perpendicular lines—lines that form right angles.
1-6 Polygons
Polygon—a closed figure whose sides are all segments.
Concave polygon—a polygon for which there is a line containing a side of the polygon that also
contains a point in the interior of the polygon.
Convex polygon—a polygon for which there is no line that contains both a side of the polygon
and a point in the interior of the polygon.
n-gon—a polygon with n sides.
Regular polygon—a convex polygon in which all of the sides are congruent and all of the angles
are congruent.
Perimeter—the sum of the lengths of the sides of a polygon.