Download ACUTE ANGLE RIGHT ANGLE OBTUSE ANGLE

ACUTE ANGLE
An angle with a
measure less than 90˚
RIGHT ANGLE
An angle with a
measure of exactly 90˚
OBTUSE ANGLE
An angle with a
measure greater than
90˚ but less than 180˚
STRAIGHT ANGLE
An angle with a
measure of exactly
180˚
RIGHT TRIANGLE
A triangle with one
right angle
REGULAR
(Equilateral,
Equiangular)
A triangle with three
congruent sides and
three congruent angles
VERTEX
The endpoint of two
rays that form an angle
RAY
The part of a line that
continues in one
direction from a single
point
COMPLEMENTARY
ANGLES
Angles whose sum is
90˚
m
A + m  B = 90˚
SUPPLEMENTARY
ANGLES
m
A + m  B = 180˚
Angles whose sum is
180˚
ADJACENT ANGLES
Angles that share a
common vertex and
ray
LINEAR ANGLES
Adjacent angles that
also share a line
A
VERTICAL ANGLES
B
D
C
mA = m C
mB = m D
A pair of opposite
angles formed when
two lines meet at a
point
INTERSECTING LINES
Lines that cross at a
point
PERPENDICULAR
LINES
Two lines that
intersect at a right
angle