Download Ch.1 Vocab List

Acute Angle
An angle less than 90
degree
Adjacent angles
Share a common side. Are
NEXT TO each other
Angle
Formed by two rays with a common
endpoint. Named by ABC
Angle Bisector
A line/ray/segment that divides an angle
in ½, or into two congruent parts
Collinear
Points on the SAME LINE
Complementary Angles
Add to 90 degrees
Congruent Segments &
Angles
Have the same measure
Coplanar
Points on the SAME
PLANE
Intersection
The set of points that two or more
geometric figures have in common.
Line
*Made up of points extending
infinitely in both directions.
Line Segment
Has two endpoints.
Linear Pair of Angles
Adjacent angles that form a
straight line
M is "Between" points X &
Y
M,X, and Y are Collinear and XM + MY =
XY.
Part 1 + Part 2 = whole
Midpoint
AVERAGE!!!! Add Xs and
Add Ys and Divide by 2
Obtuse Angle
An angle greater than 90
and less than 180
Perpendicular Lines
Intersect to form right
angles
Plane
*A flat surface made of points
extending infinitely in all directions.
Point
A location in space; no shape or
size, named by a Capital letter
Ray
Has one endpoint and extends in one
direction XY, (start with endpoint)
Right Angle
90 degree angle
Supplementary Angles
Add to 180 degrees
Vertex
The common endpoint of the
rays/sides that form an angle
Vertical Angles
Two NON-adjacent angles formed by
intersecting lines. Opposite sides of X.
"Kissing"