1. Lesson 9-3 Example 4 9-3 Solve. GEOMETRY The perimeter of a trapezoid is the sum of the length of its sides. One side length is 16 inches. One side length is 7 inches. Another side length is 25 inches. Write an expression for the perimeter of the trapezoid. Understand Read the problem. Write what you know. The perimeter of a trapezoid is the sum of the lengths of 4 sides. One side is 16 inches. One side is 7 inches. One side is 25 inches.

2. Lesson 9-3 Example 4 9-3 Plan Pick a strategy. One strategy is to draw a diagram. Sketch the trapezoid. Choose a variable for the length of the unknown side. The operation to use is addition.

3. Lesson 9-3 Example 4 9-3 Solve Write the expression for the perimeter. 16 + 7 + 25 + x Simplify the expression. 48 + x

4. Lesson 9-3 Example 4 9-3 Check Does the expression make sense? The perimeter of the trapezoid should be greater than the length of the three known sides combined.