Transcript Triangles - JasonMellas

Geometry:
Triangles
By:
Mr. Mellas
Triangles
Classified by the angles they contain.
Three types
-Acute, Obtuse, and Right

Acute- All acute angles
Obtuse- One obtuse angle
Right- One right angle
Acute Triangles
Example
Notice that all
angles are less than
90°. Therefore, this
is an acute triangle.
60°
60°
60°
Obtuse Triangles
Example
30 °
Obtuse Angle
130°
20°
This is an obtuse triangle
because there is one
angle that is greater than
90°.
Right Triangle

Example
Right Angle
This is a right
triangle because
there is one angle
that is 90°
Measurement

You need to remember that in
every triangle, all angles have to
equal 180° when the sum of the
angles is found.
60 + 60 + 60 = 180
60°
60°
60°
Finding Angle Measurements

You need to remember that all angles
total 180°.
Notice that you have 2
angles given already.
- Find their sum, then
subtract from 180
50°
1. 90 + 50 = 140
x
2. 180 – 140 = 40
3. Angle x = 40°
Other Examples

Solve for x.
85°
x
x
55°
46°
X = 49°
X = 96°
29°
Remembering Angle
Relationships

Remember vertical angle rules
B
50°
Solve for x
A
Since angle DCE = 90°
then angle CED = 35°
55°
C
x
E
D
Remembering Angle
Relationships

Remember supplementary angle rules
M
L
Since angle LPM = 75° then
angle MPN = 105° because
they are supplementary.
75°
x
P
N
Your Turn

Solve for the missing angles
30˚
Angle X= 70˚
80˚
Angle Y = 70˚
x
Angle Z = 35˚
Y
Z
75˚