The document discusses triangle inequalities and properties of triangles. It asks questions about determining the largest and smallest angles of a triangle based on side lengths, ordering sides from greatest to least, and properties of exterior angles. Specifically, it notes that the exterior angle is equal to the sum of the remote interior angles.

1. Warm Up: pg. 218 # 19-20

3. 4.3 Tiangle Inequalities pg. 213 to 218
There are many different kinds of triangles:
What happens when the length of the yellow line changes?
(blue and red line are ≅ and do not change in length)

4. When you make a triangle the goal is to have a
shape with 3 sides
Can you make a triangle out of these three lines?
What do you have to know about the measures of the
sides to make a triangle?

5. So what does this mean......
Let's see what the Dynamic Exploration does......
http://www.keymath.com/x3017.xml

6. So, using this information, HOW do you find which angle is
the largest and which one is the smallest angle in a
triangle? pg. 215
So let's try it, Which is the largest angle and
what side is opposite ?

7. So then... WHAT goes in the blank?
Which side has shortest length, WHY?
35°
a
c
Which side has longest length, WHY?
55° 90°
b

8. Let's Try It.....
c
a
60°
70°
b
Order the sides from greatest to least

9. So far we have studied Interior angles of triangles,
What about exterior angles..... pg. 215

10. See if you can get these answers AND then tell me what
goes in the blank for C-23 on pg. 216
HINT: What do you notice about the angles that DO NOT
share a vertex?

11. Let's fill it in.....

12. Let's try some practice....