Download Adjacent Angles-2 coplanar angles that share a common ray

Angles
(def) An ACUTE ANGLE is an angle w/ a MEASURE less
than 90°
(def) A RIGHT ANGLE is an angle w/ a MEASURE = 90°
(def) An OBTUSE ANGLE is an angle w/ a MEASURE
greater than 90° but less than 180 °.
(def) A STRAIGHT ANGLE is an angle w/ a MEASURE =
180°
Interior of angle
Exterior of angle
To Name an Angle- either use 3 letters or number it, never use
only 1 letter unless there is only one angle with that vertex. If
you use three letters, the vertex must be the middle letter.
D
A
ABD or
1
B
E
1 never use B
in this type of problem since more than
one angle has a vertex of B.
(def) ADJACENT ANGLES are 2 coplanar angles that share a
common ray and vertex but no common interior pts.
(def)An ANGLE BISECTOR is a ray that divides an angle
into 2 congruent angles.
ABD  DBC
A
D
B
C
ANGLE ADDITION POSTULATE- If D is in the interior of
ABC , then mABD  mDBC  mABC
A
D
B
C
i.e. The sum of the parts = whole
(def) SUPPLEMENTARY ANGLES are 2 angles whose
measures have a sum of 180°
or
145°
35°
(def) COMPLEMENTARY ANGLES are 2 angles whose
measures have a sum of 90°
or
50°
40°
(def) LINEAR PAIR ANGLES are 2 adjacent angles whose
non-common sides form a line.
Linear Pair Theorem- If 2 angles form a linear pair, then
they are supplementary.
(def) VERTICAL ANGLES are 2 nonadjacent angles
formed by intersecting lines
1
4
2
3
Vertical Angles Theorem- If 2 angles are vertical angles,
then they are congruent.