1 / 26

Angles

Acute Angle

An angle that measures between 0 and 90 degrees.

Right Angle

An angle that measures 90?.

Obtuse Angle

An angle that measures between 90 and 180 degrees.

Straight Angle

An angle that measures 180?.

Reflex Angle

An angle with measure between 180 and 360 degrees.

Vertical Angles

Two angles across from each other when two lines

intersect.

Name 2 pairs of vertical angles.

?1 ?3 ?2 ?4

Perpendicular Lines

Two lines that intersect to form right angles.

Adjacent Angles

Two angles that share a vertex and ray, but no

interior points (dont overlap).

Not Adjacent Angles

Why?

a

s

b

r

Name 4 pairs of adjacent angles.

?1 ?2 ?2 ?3 ?3 ?4 ?1 ?4

Complementary Angles

Two angles with measures that add up to 90.

Find the value of y.

y

30?

y 90 - 30 60

Supplementary Angles

Two angles with measures that add up to 180.

Linear Pair of Angles

Two adjacent angles that form a line.

Find the value of x.

x 180 - 40 140

Find x and y.

x 60 y 180- 60 y 120

What would they measure?

What would they measure?

More Examples 1

(3x 2)?

x?

X 22

Example 2

(3x 6)?

2x?

X 34.8

Examples 3

- ? ABC and ? CBD form a right angle.
- m? ABC 3(m? CBD). How much does each angle

measure?

m? CBD 22.5 m? ABC 67.5

Example 4

- RST ? ? TSW
- m? RSW 95?

Each angle measures 47.5 degrees

Example 5

- RM bisects ? LRX.
- m ? LRM 6x 9
- m ? MRX 3x 12

Source

http//jwilson.coe.uga.edu/interMath/MainInterMath

/Dictionary/ http//access.selkirk.bc.ca/math/Mod

ule_4/Mod4_Pt1/mod4_pt1.html http//www.800score.

com/guidetc.html