Download Vocabulary Chapter 1A

Geometry Vocabulary
Chapter 1A
You should be familiar with these terms. There will be a multiple choice quiz in two days. You MUST be
able to answer at least 80% of the questions correctly. Failure to do so will result in additional
homework.
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Point-names a location and has no size
Line-is a straight path that has no thickness and extends forever
Plane-is a flat surface that has no thickness and extends forever
Line segment-part of a line consisting of two points and all points between them
Ray-part of a line that starts at an endpoint and extends forever in one direction
Length- the distance between the two endpoints of a line segment
Angle-figure formed by two rays (sides) with a common endpoint
Vertex (of an angle)- common endpoint
Interior of an angle- set of all points between the sides of the angle
Exterior of an angle- set of all points outside the angle
Measure of an angle- number that corresponds to the size of the angle, usually given in degrees
Acute angles- angles with a measure greater than 0° and less than 90°
Right Angles- angles with a measure of 90°
Obtuse Angles- angles with a measure greater than 90° and less than 180°
Perimeter (of a plane figure)- (P) sum of all the side lengths of the figure
Area (of a plane)- (A) number of non-overlapping square units
Base (of a triangle)- can be any of the three sides
Height (of a triangle)- a line from a vertex that is perpendicular to the side labeled as the base
Diameter (of a circle) – (d) segment that passes through the center and whose endpoints are on
the circle
Radius (of a circle)- (r) segment whose endpoints are the center of the circle and a point on the
circle
Circumference (of a circle)- (C) the distance around the circle
Coordinate plane- plane divided into four quadrants by the x and y axis
Ordered pair- location on the coordinate grid (x,y)
Right triangle- triangle that has a right angle