Bellwork, Monday April 1, 2019 Turn in your Math Notebook and do each of these Bellwork problems on Page 26. Turn to your Table of Contents in your Math Notebook. On Line 27: Circumference and Volume of Circles and Cylinders

Crop Circle “Math” Circles Obj. 4b

Crop Circles The Crop Circle “frenzy” emerged in 1979 when circles started appearing in Southampton, England. UFOlogist used the patterns as “PROOF” that Extraterrestrials existed. They believed that the patterns were too complicated to be man-made.

Crop Circles Crop circles are patterns created by the flattening of crops such as wheat, barley or corn. The term “Crop Circle” was first used by a researcher named Colin Andrews to describe simple circles he was researching. Since 1990 the circles have evolved into complex geometric shapes; however the term “Crop Circles” has stuck. Many theories have emerged as to where these crop circles have come from ranging from man-made hoaxes to UFOs.

Crop Circles

Crop Circles 2010 Found Italy England Italy England England England Russia Ice Circle Netherlands

Turn to page 26 in your Notebook and add these definitions. New Vocabulary Turn to page 26 in your Notebook and add these definitions. Radius – Is the distance from the center of the circle to the outer edge. Diameter – Is the distance from one side of the circle to the other. Pi – Is a number used when working with circles. (Also known as 3.14) The symbol for pi is .

Circumference 2 x 3.14 x 7 3.14 x 14 Finding the Circumference The distance around a circle is call its Circumference (C). There are two formulas you can use to find the circumference. Each formula uses pi. π = 3.14   7 m Radius (r) 14 m Diameter (d) C = 2 π r C = πd C = ___________________ C = _____________________ 2 x 3.14 x 7 3.14 x 14

Area Finding the Area 3.14 x 8² 3.14 x 8² The Area (A) is the amount of space inside a circle. Radius (r) Diameter (d) Find the radius: 16 ÷ 2  8 A = π r A = π r A= ____________________ A = ____________________ 8 m 16 m 2 2 3.14 x 8² 3.14 x 8²

Discovered : June 24, 1997 Oxfordshire, England Top circle – 15 ft diameter Bottom circle – 17 ft diameter Left circle – 16 ft diameter Right circle – 14 ft diameter Center circle – 64 ft diameter Diameter: The distance from one side of the circle to the other. Radius: The distance from the center of the circle to the outer edge.

3.14 x 15 = 47.1 3.14 x 17 = 53.38 3.14 x 16 = 50.24 3.14 x 14 = 43.96 3.14 x 64 = 200.96

7.5 176.625 8.5 226.865 8 200.96 7 153.86 32 3,215.36

𝝅 8² 22 4,423.36 𝝅 2² 7 87.96 𝝅 10² 17 5,340.71

11,304 cm³ 588.8 m³ 3,215.5 ft³ 4 in³ 5,652 mm³ 648.1 ft³ 3,231.1 cm³ 282.6 cm³ 1,177.5 in³