Introduction To Geometry Summary Sheet (Page 2 of 4) in pdf

Ch 1 Summary

Name ____________________________

Lines and Parts of Lines

Angles

line segment Two points and all the points between them

angle Two noncollinear rays having a common endpoint.

that are collinear with the two points. Also called a

vertex (of an angle) The common endpoint of the two rays of the angle.

segment. The measure of a line segment is its length.

side (of an angle) One of the two rays that form an angle.

endpoint The point at either end of a segment or arc, or

measure of an angle The smallest amount of rotation about the vertex

the first point of a ray.

from one ray to the other, measured in degrees.

midpoint The point on a line segment that is the same

degree A unit of measure for angles and arcs. 360 of a rotation around a

distance from both endpoints. The midpoint bisects the

circle. (protractor A tool used to measure the size of an angle in

segment.

degrees.)

ray A point on a line, and all the points of the line that lie

on one side of this point.

congruent angles Two or more angles that have the same measure.

congruent segments Two or more segments that have the

angle bisector A ray that has its endpoint at the vertex of the angle and

same measure or length.

that divides the angle into two congruent angles.

adjacent angles Two non-overlapping angles with a common vertex and

Types of Lines:

one common side.

perpendicular Lines are perpendicular if they meet at 90°

angles. Line segments and rays are perpendicular if they lie

Types of Angles:

Types of Pairs of Angles:

on perpendicular lines.

right angle An angle whose

complementary angles Two angles

parallel Lines are parallel if they lie in the same plane and

measure is 90°.

whose measures have the sum 90°.

do not intersect. Line segments or rays are parallel if they

acute angle An angle whose

supplementary angles Two angles

lie on parallel lines.

measure is less than 90°.

whose measures have the sum 180°.

skew lines Lines that are not in the same plane and do not

obtuse angle An angle whose

vertical angles Two nonadjacent angles

intersect.

measure is greater than 90°,

formed by two intersecting lines.

but less than 180°.

linear pair (of angles) Two adjacent

angles formed by a line and a ray.

Introduction To Geometry Summary Sheet Page 2

Related Articles

Related forms

Related Categories