1. Objective: Find the areas of trapezoids Homework: p550-551, #14-16, 18, 22-24 10.3 Areas of Trapezoids

2. Key Terms Base of a Parallelogram: _______________________________________________ _____________________________________ Height of a Parallelogram: _______________________________________________ _____________________________________

3. Area of a Trapezoid A = ½(b 1 + b 2 )h b 1 & b 2 = bases h=height Example: A=

4. Example 1: Finding the area of a Trapezoid The diagram shows one of the trapezoids in a quilt design. Find the area of the trapezoids. A = ½(b 1 + b 2 )h 2.5 cm 9 cm 4 cm

5. Example 2: Finding the area of a Trapezoid Find the area of the trapezoid.A = ½(b 1 + b 2 )h 1.) 2.) 9 ft 8.5 ft 16 in. 22 in. 3 ft 13 in.

6. Example 3: Finding an Unknown Length The height of a trapezoid is 6 meters. One of its bases is 8 meters. The area of a trapezoid is 54 square meters. Find the other base. A = ½(b 1 + b 2 )h

7. Example 4 : Using Area of Trapezoids You are building an L-shaped desk for your room. The dimensions of the desktop are shown. Find the area of the desktop. A = ½(b 1 + b 2 )h

8. Checkpoint One base of a trapezoid is 9 feet, and the height is 4 feet. The area of the trapezoid is 28 square feet. Find the other base. A = ½(b 1 + b 2 )h