1. Area & Perimeter of Triangles

2. The formula for a triangle can be determined from using parallelograms. Cut a parallelogram in half it forms 2 triangles. Not in notes

3. Therefore, a triangle’s area is ½ of the area of a parallelogram. Not in notes

4. h b A = 1212 bh The area A of a triangle is half the product of its base b and its height h. The perimeter of a triangle - add the three sides that form the triangle. h 1 2 3

5. Find the area of the triangle. 5 8 A = 1212 bh Use the formula. A = 1212 (8 · 5) Substitute 8 for b and 5 for h. A = (40) EX1) 9 A = 1212 bh A = 1212 (9 · 12) A = 54 12 EX2) 1212 A = 20 A = 1212 (108)

6. notes

7. Area & Perimeter of Triangles Date _____________

8. The area A of a triangle The perimeter of a triangle - h

9. Find the area of the triangle. EX1) EX2)