Distorted pasta strainers illustrate possible choices for closed surfaces.
These three-dimensional models can be used. if so desired, to illustrate some variety in choice of closed surfaces when referring to Gauss' Law or Stokes' Theorem.
Invite students to handle them and experiment with different distortions of the form; show that the surface area remains (approximately) invariant.
						Illustrate a standard right-handed cartesian coordinate system						Read More
					
						Aid in discussing angular momentum						Read More
					
						Show the relationship between the diameter and the circumference of a circle						Read More
					
						Demonstrate rotation and spherical geometry						Read More
					
						Demonstrate one method of drawing ellipses						Read More
					
						Illustration of the conic sections						Read More
					
						Approximate the hyperboloid						Read More
					
						Illustrate the geometry of a saddle point						Read More
					
						Illustrate various complicated closed curves						Read More
					
						Demonstrate properties of vectors						Read More
					
						Demonstration of vector properties						Read More
					
						Illustrate the product of two vectors						Read More
					
						Illustrate aspects of vector algebra						Read More
					
						Determine the height of a student using trigonometry
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						Aid in perception of the components of a three-dimensional vector
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						Demonstrates Gaussian distribution						Read More