# Radius Of A Cylinder

1): My directions, incl SA of .5 in: I cut the fabric 19 in wide. I use 2 pieces of fabric: it’s easier to insert zip. If the radius of the circle is 7 1/2 in w/o S.A, the total width must fit around. So I cut the shorter width WIDER than necessary & cut it later to fit. The longer width is about 23 inches and the shorter width about 3 inches. When fitting the tube to the cylinder, excess can be cut off. The insert should be an inch longer and wider than the form.

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Comparing Volumes of Cylinders, Spheres, and Cones- In this interactive from Annenberg Learner’s Learning Math, compare the volumes of a cylinder, cone, and sphere that all have the same radius and height. In the accompanying classroom activity, students fill cylinders, spheres, and cones with water in order to compare volumes of shapes with equal height and radius. They use the interactive to further explore the concept.

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