1. Find the function rule for the function table.
Warm Up Problem
Find the function rule for the function table.
Input (x)
Output (y) 1 7 2 12 3 17 4 22

2. Area of Triangles
Lesson 9-2

3. Objectives
I can find the area of a triangle. Given the area, I can find the missing dimension of a triangle.

4. Vocabulary
congruent – figures that are the same shape and size **They are EXACTLY the same**

6. Example 1 A = 1 2 · 6 · 4 A = 1 2 · 24 A = 12 units²
Find the area of the triangle.
A = · 6 · 4
A = · 24
A = 12 units²

7. Example 2 A = 1 2 bh A = 1 2 12.1 · 6.4 A = 1 2 · 77.44 A = 38.72m²
Find the area of the triangle.
A = 1 2 bh
A = · 6.4
A = · 77.44
A = 38.72m²

8. Got It?
Find the area of each triangle.

9. Example 3
Find the missing dimension of the triangle. Formulas: base = 2(Area) ÷ height height = 2(Area) ÷ base base = 2(Area) ÷ height base = 2(24) ÷ 6 base = 48 ÷ 6 base = 8 cm

10. Got It? Find the missing side length for each triangle.
Formulas: base = 2(Area) ÷ height
height = 2(Area) ÷ base

11. Example 4
The front of a camping tent has the dimensions 5ft by 3ft. How much material was used to make the front of the tent? A = 1 2 (5)(3) A = 1 2 (15) A = 7.5 A = 7.5 sq. ft.

12. Homework Hints
7c. In other words, “Does the graph show a line or a curve?”. 8. Be sure to convert the feet into inches. The answer is not 15 feet2 although it is equal to 15 feet When it asks you to make a ratio, follow this formula: 𝒔𝒎𝒂𝒍𝒍𝒆𝒓 𝒂𝒓𝒆𝒂 𝒍𝒂𝒓𝒈𝒆𝒓 𝒂𝒓𝒆𝒂 and then simplify the fraction in lowest terms.