Investigation 7.1Pricing Pizza

TenikaEarline

LisaByron

There are four measurements that are useful for describing

the size of a circle:

• Diameter• Radius• Circumference• Area

Diameter

•The diameter cuts the pizza into two equal halves.

Radius

•The radius is half of the diameter–It goes from the center of the pizza to the crust.

Circumference

• The circumference is the crust of the pizza.

• Circumference means perimeter in the language of circles.

Area

• The area of a circle is the number of square units inside that circle.

• The toppings on the pizza

Problem 7.1

• The Sole D’ Italian Pizzeria sells small, medium, and large pizzas. A small pizza is 9 inches in diameter, a medium is 12 inches in diameter, and a large is 15 inches in diameter. Prices for cheese pizza are $6.00 for a small, $9.00 for a medium, and $12.00 for a large.

Problem 7.1 Continued

A. Draw a 9 –inch, a 12-inch, and a 15-inch “pizza” on centimeter grid paper. Let 1 centimeter of the grid paper represent 1 inch on the pizza. Estimate the radius, circumference, and area of the pizza. (You may want to use string to help you find the circumference.)

Collecting DataSize Diameter Radius Circumferen

ceArea

Small

Medium

Large

Collecting Data

Size Diameter Radius Circumference

Area

Small 9 inches 4.5 inches

28.3 inches

63.6inches2

Medium 12 inches 6 inches

37.7 inches

113.1inches2

Large 15 inches 7.5 inches

47.1 inches

176.7inches2

Problem 7.1 Continued

B. Which measurement – radius, diameter, circumference, or area – seems most closely related to price? Explain your answer.

Reference:

Teachertube.com- HomeAlonevideo

ACE Problems

• Bring in circular objects to use in the next problems