1. Splash Screen

2. Five-Minute Check (over Lesson 13–4) Main Idea
Example 1: Problem-Solving Investigation
Lesson Menu

3. I will choose the best strategy to solve a problem.
Main Idea/Vocabulary

4. EMILIO: To make a quilt pattern, I pieced together triangles to make squares of different sizes. The first square is made from 2 triangles, the second square is made from 8 triangles, and the third square is made from 18 triangles. The quilt will have squares of five different sizes.
Example 1

5. YOUR MISSION: Find how many triangles are in the fifth square.
Example 1

6. Understand What facts do you know?
There are 2 triangles in the first square.
There are 8 triangles in the second square.
There are 18 triangles in the third square.
Example 1

7. Understand What do you need to find?
You need to find how many triangles are in the fifth square.
Example 1

8. Plan
Look for a pattern to find the number of triangles.
Example 1

9. Solve Each square has twice as many triangles as small squares.
First square
2 × 1 or 2 triangles
Second square
2 × 4 or 8 triangles
Third square
2 × 9 or 18 triangles
Continuing the pattern, the fourth square has 2 × 16 or 32 triangles. The fifth square has 2 × 25 or 50 triangles.
Example 1

10. Check
Draw the fifth square and count the number of triangles. Since there are 50 triangles in the fifth square, the answer is correct.
Example 1

11. End of the Lesson
End Lesson

12. Five-Minute Check (over Lesson 13–4) Image Bank Math Tool Chest
Identify Angles
Resources

13. True; opposite sides are parallel and all sides are congruent.
(over Lesson 13–4)
Determine whether the statement is true or false. Explain. All squares are rhombi.
True; opposite sides are parallel and all sides are congruent.
False; all rhombi are squares.
False; only some squares are rhombi.
False; squares are never rhombi. A B C D
Five Minute Check 1

14. True; parallelograms with 2 parallel sides are rectangles.
(over Lesson 13–4)
Determine whether the statement is true or false. Explain. Some parallelograms are rectangles.
True; parallelograms with 2 parallel sides are rectangles.
True; parallelograms with 4 right angles are rectangles.
False; all parallelograms are rectangles.
False; parallelograms are never rectangles. A B C D
Five Minute Check 2

15. True; all rhombi have 4 congruent sides.
(over Lesson 13–4)
Determine whether the statement is true or false. Explain. All parallelograms are rhombi.
True; all rhombi have 4 congruent sides.
False; parallelograms can never be rhombi.
False; only parallelograms with 4 congruent sides are rhombi.
True; parallelograms with 4 right angles are rhombi. A B C D
Five Minute Check 3

16. False; all rectangles are squares.
(over Lesson 13–4)
Determine whether the statement is true or false. Explain. Some rectangles are squares.
False; all rectangles are squares.
False; rectangles can never be squares.
True; rectangles with 4 congruent sides are squares.
True; rectangles are always squares. A B C D
Five Minute Check 4

17. End of Custom Shows