Stage: 4 Challenge Level: 
What is the volume of the solid formed by rotating this right angled triangle about the hypotenuse?
Can you generalise this for any right angled triangle with sides of length $a$, $b$ and $c$, where $b$ is the hypotenuse?
Cones. Rotations. Volume and capacity. Mathematical reasoning & proof. Complex numbers. Reflections. Manipulating algebraic expressions/formulae. Generalising. Making and proving conjectures. Right angled triangles.
Published February 2003.
Copyright © 2007. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project, which also includes the Plus and Motivate sites.
email: nrich@damtp.cam.ac.uk
