Unit 1 Module 1 Vocab

point

a specific location. it has no dimension and is represented by a dot

line

a connected straight path. it has no thinkness and continues forever in both directions

plane

a flat surface. it has no thickness and extends forever in all directions

segment

portion of a line consisting of two points and all points between them

endpoints

point(s) on the end

ray

a portion of a line that starts at a point and continues forever in one direction

coplanar

points that lie on the same plane

parallel

lines that lie in the same plane but do not interect

collinear

points that lie on the same line

postulate

a statement that is accepted as true without proof

midpoint

the point that divides a segment into two segments that have the same length

segment bisector

a line, ray or other figure that passes through the midpoint of a segment

sketch

freehand

draw

using the tools of measurement - a ruler and protractor

costruct

using the tools of construction - a straight edge and compass

angle

a figure formed by two rays with the same endpoint

vertex

the common endpoint of two rays in one angle

sides

the rays of an angle

degrees

a measurement unit for circular arcs

angle bisector

a ray that divides an agnle into two angles that both have the same measure

transformation

a function that changes the position, shape, and/or size of a figure

translation

slide

reflection

fold

roation

rotate

preimage

a figure that is used as the imput of a transformation

image

a figure that is the output of a transformation

prime notation

name the image of a point. Example: B a B read as "B prime"

mapping

another name for transformation. transformation T maps A to A prime

coordinate plane

one way to write a rule for a transformation on a coordinate plane

rigid motion

a transformation that changes the position of a figure without changing the size or shape of the figure

conjecture

a statement that is believed to be true

inductive reasoning

process of reasoning that a rule or statement may be true by looking at specific cases

deductive reasoning

process of using logic to prove whether all cases are true

theorem

a statement that you can prove is true by using a series of logical steps

counterexample

an example that shows a conjecture to be false

conditional statement

a statement that can be written in the form "If p, then q." where p is the hypthesis and q is the conclusion

linear pair

a pair of adjacent angles whole noncommon sides are opposite rays