1. Classifying Triangles Review!
1/5: Apply the triangle sum theorem & exterior angle theorem to solve for missing angle measures.
Do Now:
Have Out:
- Today’s Handouts
- Your Thinking Caps!
Classifying Triangles Review!
Agenda:
Do Now! & Check
Guided Notes
Independent Practice
Closing & Exit Ticket
Homework
Worksheet
(12 problems)
1st Period

2. Apply the triangle sum theorem & exterior angle theorem to solve for missing angle measures.
When you finish Do Now:
Flip Over
Write down objective
Complete warm-up

3. 145⁰ E
58⁰
87⁰
35⁰
m∠DFE = 35 ⁰
∠DEF = 180
m∠DEF = 87 ⁰
145⁰
145⁰
When you add the two non-adjacent interior angles together, you get the measure of the exterior angle.

4. The sum of the three interior angle measures of any triangle is equal to 180⁰
In + In + In = 180
The sum of the two nonadjacent interior angle measures of any triangle is equal to the measure of the exterior angle.
In + In = Out

5. Triangle Exterior Angle Theorem
In + In = Out
= m∠2
72⁰
108⁰
m∠2 = 72 ⁰
Obtuse Triangle

6. Triangle Exterior Angle Theorem
In + In = Out
75⁰
145⁰
35⁰
x + 70 = 2x – 5
x + 75 = 2x
m∠JKM = 2x – 5
-x x
m∠JKM = 2(75) – 5
75 = x
m∠JKM = 145⁰
Acute Triangle

7. Complete IP #1-10