1. U6L3 Area of Triangles & Trapezoids Do Now: Write in planner Get out homework to check/grade Set up for notes Find the circumference and area:

2. Area of a Triangle The area of a triangle is half the product of its base b and its height h.

3. Triangles A diagonal of a parallelogram divides the parallelogram into 2 congruent triangles. The area of each triangle is half the area of the parallelogram The base of the triangle can be any side. The height is the perpendicular distance from the base to the opposite vertex.

4. Practice **Hint**: multiplying by ½ is the same as dividing by 2

5. Area of trapezoids The area of a trapezoid is half its height multiplied by the sum of the lengths of its two bases

6. Trapezoids A parallelogram can be divided into 2 congruent trapezoids. The two parallel sides of a trapezoid are its bases A = ½  (b1 + b2)  h

7. Challenge Problem Find the missing measurement of each triangle. b = 12in h = ? A = 42 42 = ½ b(12) 42 = b  6 6 7= b

8. Assignment P. 436-437 #7-9, 13-15, 25