1. Bellwork
1) AG = 18 cm. What is AD?
2) Solve for x.

2. 5-5 Inequalities in Triangles
Rigor - Apply inequality theorems to triangles
Relevance – Positioning and design

3. Ordering sides and angles
Theorem – If 2 sides of a triangle are not congruent, then the larger angle is opposite the longer side and vice versa.
EX 1: Order the sides from shortest to longest

4. Examples 2 and 3:
2) Order the angles from largest to smallest.

5. Honors: Workbook Examples
Turn to workbook page and complete examples 1 & 2.

6. Can any 3 lengths make a triangle? Let’s explore!
Break into groups of 4
Find 3 color combinations that WILL connect to make a triangle. Record the colors used.
Find 3 color combinations that will NOT connect to make a triangle. Record the colors used.
Make a conjecture to the rule that must apply for 3 lengths to form the sides of a triangle.

7. Triangle Inequality Theorem – the sum of the lengths of 2 sides of a triangle is greater than the length of the 3rd side.
Small + medium > large
EX 4: Can the 3 lengths form a triangle?
A) 3ft, 7ft, 12ft
B) 5in, 4in, 3in
C) 1m, 3m, 2m

8. Finding the Range of Possible Side Lengths of a Triangle
EX 5: A triangle has side lengths of 9 in and 6 in. What is the range of possible lengths for the third side?
2 options: the third side either is or is not the longest side.
Difference < x < Sum
9-6 < x < 9 + 6

9. EX 7: What is the range of possible lengths for the third side of the triangle?
C) 13, 13, ?

10. 5-5 Classwork
Textbook pg 348 – 349
#18 – 21, 26, 28,