The right cone is the second solid of revolution: it is generated by rotating a right triangle about one of its legs.

Property — Right cone

Right cone (from the rotation of a right triangle about a leg): base radius rr, height hh, slant height =r2+h2\ell = \sqrt{r^2+h^2} (the hypotenuse of the triangle).

  • V=13πr2hV = \tfrac{1}{3}\pi r^2 h
  • Slat=πrS_{\text{lat}} = \pi r\ell
  • Stot=πr(r+)S_{\text{tot}} = \pi r(r+\ell)

Topics: Synthetic geometry of space
Concepts: Apothem · Cone · Solids of revolution · Surface area · Volume
Skills: Using formulas