Area and Cost Calculations

This lesson covers three methods to find the area of composite figures: using grid paper, dividing into simpler shapes, and enclosing with a rectangle. It includes practical problems like calculating the cost of sod for a backyard and glass for a table. The lesson concludes with a preview of the next topic on surface area.

Which of the following is NOT a method to find the area of a composite figure?

• Using grid paper to count squares

• Enclosing the figure with a rectangle

• Dividing the figure into simpler shapes

• Using a protractor to measure angles

In the example of laying sod, what is the total area of Dave's backyard?

• 20 square yards

• 24 square yards

• 30 square yards

• 28 square yards

How much does it cost to lay sod in Dave's backyard?

• $260.00

• $259.00

• $258.80

• $259.20

What is the first step in finding the area of an irregular shape by enclosing it with a rectangle?

• Subtract the area of the triangles

• Draw a rectangle around the figure

• Calculate the area of the rectangle

• Count the number of vertices

What is the total area of the irregular shape after subtracting the triangles from the rectangle?

• 30 units square

• 25 units square

• 35 units square

• 40 units square

In the example of the stretched-out circle, what is the area of the circle part?

• 30.00 feet squared

• 25.00 feet squared

• 28.26 feet squared

• 32.00 feet squared

How much does the glass cost to cover Sophia's grandmother's table?

• $261.30

• $263.50

• $260.00

• $262.00

What is the method used to find the area of a shape that looks like a rectangle with a circle cut out?

• Divide the area of the rectangle by the circle

• Add the area of the rectangle and circle

• Subtract the area of the circle from the rectangle

• Multiply the areas of the rectangle and circle

What is the next topic after lesson 9.3?

• Solving volume problems

• Modeling surface area of a prism

• Calculating perimeter

• Understanding angles

What should you remember when dealing with composite figures?

• Separate into the least amount of simple figures

• Use as many simple figures as possible

• Count the number of vertices

• Always use a rectangle to enclose the figure