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Example 9.40 from Prealgebra, 9.4 Use Properties of Rectangles, Triangles, and Trapezoids
Use Properties of Rectangles, Triangles, and Trapezoids: example 9.40
Vinny has a garden that is shaped like a trapezoid. The trapezoid has a height of yards and the bases are and yards. How many square yards will be available to plant?
Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.
Solution
Step 1. Read the problem. Draw the figure and label it with the given information. Step 2. Identify what you are looking for. the area of a trapezoid Step 3. Name. Choose a variable to represent it. Let A = the area Step 4.Translate.
Write the appropriate formula.
Substitute.Step 5. Solve the equation. Step 6. Check: Is this answer reasonable?
Yes. The area of the trapezoid is less than the area of a rectangle with a base of 8.2 yd and height 3.4 yd, but more than the area of a rectangle with base 5.6 yd and height 3.4 yd.
Step 7. Answer the question. Vinny has 23.46 square yards in which he can plant.
Your turn
The book's Try It right after this example: same idea, new numbers. Only the answer is given.
Lin wants to sod his lawn, which is shaped like a trapezoid. The bases are yards and yards, and the height is yards. How many square yards of sod does he need?
How did it go?