1. Splash Screen

2. Lesson Menu Five-Minute Check (over Lesson 10–4) Main Idea Example 1:Use the Make a Model Strategy

3. Main Idea/Vocabulary Solve problems by making a model.

4. Example 1 Use the Make a Model Strategy Solve. Use the make a model strategy. SOUP CANS Soup cans in a grocery store display are arranged in the shape of a triangle. The top row has one can and each row below it has one more can than the previous row. How many rows are there in the display if 28 cans of soup are used? UnderstandYou know there are 28 cans of soup to be stacked in the shape of a triangle. Each row in the triangle has one more can than the previous row. You need to know how many rows are in the display.

5. Example 1 Use the Make a Model Strategy PlanMake a model using 28 blocks to find the number of rows in the display. SolveBegin with 30 blocks. Place one block to represent the one can in the top row. For the next row, place two blocks under the first block. For each consecutive row, continue adding one block to the amount of blocks in the previous row.

6. Example 1 Use the Make a Model Strategy Answer: So, there are 7 rows if 28 cans of soup are used. Check28 –7 – 6 – 5 – 4 – 3 – 2 – 1 leaves no extra soup cans. By continuing this pattern, 1 + 2 + 3 + 4 + 5 + 6 + 7 or 28 blocks will be needed to make 7 rows.

7. 1.A 2.B 3.C 4.D Example 1 A.5 rows B. 7 rows C.11 rows D. 15 rows Solve. Use the make a model strategy. CHAIRS Sandy is setting up chairs for the school band concert. If she places 5 chairs in the front row and each row behind the front row has two more chairs than the previous row, how many rows of chairs will be needed to seat 165 people?

8. End of the Lesson

9. Resources Five-Minute Check (over Lesson 10–4) Image Bank Math Tools Using a Net to Build a Cube Area of Triangles

10. 1.A 2.B 3.C 4.D Five Minute Check 1 A.15 cm 2 B.25 cm 2 C.30 cm 2 D.50 cm 2 Find the area of the triangle. (over Lesson 10-4)

11. 1.A 2.B 3.C 4.D Five Minute Check 2 A.41 m 2 B.80.5 m 2 C.82.5 m 2 D.165 m 2 Find the area of the triangle. (over Lesson 10-4) m m

12. 1.A 2.B 3.C 4.D Five Minute Check 3 A.250 ft 2 B.500 ft 2 C.1,000 ft 2 D.2,000 ft 2 A triangular sail is 40 feet tall and 25 feet long. What is the area of the sail? (over Lesson 10-4)

13. 1.A 2.B 3.C 4.D Five Minute Check 4 A.360 in 2 B.560 in 2 C.720 in 2 D.880 in 2 What is the area of the kite in square inches? (over Lesson 10-4)

14. End of Custom Shows