Angle
Addition
Postulate
Angle
Bisector
© Katrina Newell, 2015
Definition : If K is in the interior of ∠HIJ,
then m∠HIK + m∠KIJ = m∠HIJ .
If m∠HIK + m∠KIJ = m∠HIJ, then K is in the
interior of ∠HIJ.
Example 1: If m∠AOC = 70° , m∠AOB = ½(2x +
20)°, and m∠BOC = x°, find:
A
X = ____________
m∠ AOB = ____________
O
C
K
H
I
J
Definition : A ray that divides an angle
Example 2: FG bisects ∠EFH. If m∠GFH =
½(10x-20)° and m ∠EFG= (3x + 25)°, find:
into two congruent angles.
If XZ is an angle
bisector of ∠WXY ,
name the two
congruent angle s
that it forms.
W
Z
X
B
m∠ BOC = ____________
E
X = ____________
G
m∠ GFH = ____________
I
F
H
m∠ EFG = ____________
m∠ EFH = ____________
m∠ IFE = ____________
y