Curated OER
Tennis Ball Tubes
Learners determine whether the height of a tennis ball tube or the distance around the tube is greater, or whether they are the same. Using the formula for the circumference and diameter of a sphere, they discuss the word problem, and in...
Wolfram Research
Wolfram Math World: Sphere
This webpage thoroughly discusses the math of spheres. Includes the equation for a sphere in Cartesian and spherical coordinates as well as parametrically. Surface Area, volume, and curvature are addressed at this extensive site.