1. Ray AB or AB
An angle consists of two different rays with
the same endpoint.
Ray BA or BA
The ray symbol doesn't indicate a direction. The endpoint is always the first point used when naming a ray.
The rays that are used to make the angle.
The endpoint of the rays that make the angle.
The number of degrees (or radians) that separate
the two sides of an angle.
An angle whose measure is between 0° and 90°
An angle whose measure is 90°.
An angle whose measure is greater than 90°
and less than 180°
An angle whose measure is 180°
Angles with the same measure.
A ray that divides an angle into two
congruent angles.

2. ∠ABC ∠CBA
∠CBD ∠DBC
vertex
∠ABD ∠DBA

3. 180°
∠AOB the absolute
value difference

4. outer
You always start
counting from 0.
65°
outer
65°
an acute
inner
115°
inner
115°
an obtuse
180° a straight
90° a right

5. ∠FGJ or ∠JGF, ∠JGH or ∠HGJ and ∠FGH or ∠HGF
The x and y axis form a right angle because horizontal
and vertical lines are perpendicular.

6. RSP
PST
RSP PST

7. GFH HFJ
155° x x - 1
x + 3 x 3 19 8 19
4x (19) °
4x (19) °
80° °

8. ∠N ∠M
∠N m∠N
120°

9. ∠XWY ∠YWZ
∠XWY ∠YWZ
m∠XWY m∠YWZ
m∠XWY m∠YWZ
° °

10. ∠B ≅ ∠D and ∠A ≅ ∠ C m∠D = 135°
∠LKN = ∠LKM + MKN
∠LKN = 78° + 78°
∠LKN = 156°