Undefined Term
term that is best described using pictures. (Point, line, and plane)
Point
a dot
Line
infinite set of points
Plane
a 2D flat surface which contains points and lines.
Defined Term
Terms with definitions
Collinear
3 or more points on the same line
Coplanar
3 or more points on the same plane
Intersection
Where 2 things meet
Space
Where everything is contained
Line Segment
A line with 2 endpoints. A piece of a line
Congruent Segments
Segments of the same length
Distance
Always a positive measurement
Irrational Number
Numbers with a decimal
Distance Formula
Radical (x2-x1)^2 + (y2-y1)^2
Midpoint Formula
(x1+x2)/2, (y1+y2)/2
Midpoint
A point in the middle
Segment Bisector
Cuts a segment in half
Ray
Continues infinitely to 1 side
Opposite Rays
2 rays that share an endpoint and travel in opposite directions to form a straight line.
Side
A side of an angle, also a ray
Vertex
Shared endpoint of an angle
Degree
Measurement of an angle
Right Angle
A 90 degree angle
Acute Angle
An angle less than 90 degrees
Obtuse Angle
An angle greater than 90 degrees
Angle
Formed by 2 rays that share an endpoint
Interior
Inside
Exterior
Outside
Angle Bisector
Cuts and angle in half
Adjacent Angles
Angles that share a side
Linear Pair
2 angles that form a straight line
Vertical Angles
Opposite of each other and rays form an X
Complementary Angles
2 angles that add up to 90 degrees
Supplementary Angles
2 angles the add up to 180 degrees
Perpendicular
2 lines that form a right angle
Polygon
a closed, sided figure
Vertex of a Polygon
Where 2 sides of a shape meet
Concave Shape
When a side is extended and it passes through the interior
Convex Shape
When a side is extended and does not go through the interior
Equiangular Polygon
All angles are the same
Regular Polygon
All angles and sides are the same
Equilateral Polygon
When all sides are the same
3 Sides
triangle
4 Sides
Quadrilateral
5 Sides
Pentagon
6 Sides
Hexagon
7 Sides
Heptagon
8 Sides
Octagon
9 Sides
Nonagon
10 Sides
Decagon
11 Sides
Hendecagon
12 Sides
Dodecagon
13+ Sides
N-gon