2. Example 1: Finding the Area of a Triangle
A. Find the area of the triangle. 5 8
The area of the triangle is 20 square units.

3. Example 2: Finding the Area of a Triangle
B. Find the area of the triangle. 9 12
The area of the triangle is 54 square units.

4. Check It Out! Example 3
A. Find the area of the triangle. 9 6
The area of the triangle is 27 square units.

5. Check It Out! Example 4
B. Find the area of the triangle. 10 7
The area of the triangle is 35 square units.

6. The two parallel sides of a trapezoid are its bases, b1 and b2
The two parallel sides of a trapezoid are its bases, b1 and b2. The height of a trapezoid is the perpendicular distance between the bases. b2 h b1

7. In the term b1, the number 1 is called a subscript
In the term b1, the number 1 is called a subscript. It is read as “b-one” or “b sub-one.”
Reading Math

8. Example 5: Finding the Area of a Trapezoid
A. Find the area of the trapezoid.
5 in.
6 in.
9 in.
The area of the trapezoid is 42 in2.

9. Example 6: Finding the Area of a Trapezoid
B. Find the area of the trapezoid.
12 cm
7 cm
16 cm
The area of the trapezoid is 98 cm2.

10. A. Find the area of the trapezoid.
Check It Out! Example 7
A. Find the area of the trapezoid.
11 in.
4 in.
6 in.
The area of the trapezoid is 45 in2.

11. B. Find the area of the trapezoid.
Check It Out! Example 8
B. Find the area of the trapezoid.
16 cm
9 cm
5 cm
The area of the trapezoid is 94.5 cm2.

12. Example 9: Geometry Application
The state of Wisconsin is shaped somewhat like a trapezoid. What is the approximate area of the state?
The area of Wisconsin is approximately 56,000 square miles.