1. Lesson Plan for SD 3.1 (50 minutes): Target: I can identify what side lengths make a triangle. 5 minutesWarm-up (notebook) 15 minutesTry to build triangles will given side lengths (can use polystrips, virtual polystrips on computer/iPad). 15 minutesDiscuss the pattern for when side lengths do/not make a triangle. 10 minutesSummary statement (think, ink, pair, share – discuss as class) 5 minutesReminders: Correct homework with key (puzzle)

2. Quick Start Expectations 1.Learning Target: I can identify what side lengths make a triangle! 2. Fill in Learning Log - HW: 1) SD Inv. 3 packet p. 6 – Triangle Interior Angles 2) Math XL – 30 mins. this week 3. Warm-up: Find the missing angles in the triangle: B AC

3. x + 2x + 24 = 180 3x + 24 = 180 3x = 156 x = 52 ∠ BAD = x = 52⁰ ∠ ACB = 2x = 104⁰ ∠ CBA = 24⁰ Check: 52 + 104 + 24 = 180⁰

4. Inv. 3 - Problem 3.1: Building Triangles Virtual Polystrips http://media.pearsoncmg.com/curriculum/math/cmp3/activities/A82391/index.html http://media.pearsoncmg.com/curriculum/math/cmp3/activities/A82391/index.html Answers on next pages

5. Virtual Polystrips http://media.pearsoncmg.com/curriculum/math/cmp3/activities/A82391/index.html http://media.pearsoncmg.com/curriculum/math/cmp3/activities/A82391/index.html 3, 4, 5 1, 1, 3 2, 4, 7 2, 3, 4 Yes! No

6. 4, 5, 7 2, 3, 8 Yes! No

7. 3,4,5 2,3,4 4,5,7 1,1,3 2,4,7 2,3,8

8. If the sum of two side lengths is less than the third length, no triangle can be constructed. In no case can a given set of side lengths be used to make two different triangle shapes. Responses will vary.

9. Which sets form a triangle? Why? 4, 3, 5 and 8, 8, 4 because the sum of any two sides is greater than the third. 8, 8, 4 is isosceles since it has two equal sides. 4, 3, 5 is a right triangle because it has one 90 degree angle and is a scalene triangle since all sides have different lengths. What summary statement would help someone who is not here today know how to judge whether three lengths will make a triangle without actually building the triangle? For example: 4, 3, 58, 2, 128, 8, 4 Do any of the triangles have special properties? Describe them.

10. HW: 1) SD Inv. 3 packet p. 6 – Triangle Interior Angles 2) Math XL – 30 mins. this week