8th Grade · Geometry
Cone
8.G.C.9
Definition
A three-dimensional solid with a circular base narrowing to a single point. Its volume is (1/3)πr2h.
Teach it
Where it is taught, with guided notes, practice, homework, an exit ticket and an interactive Teacher Deck.
Examples
- V = (1/3)πr2h.
- A cone's volume is exactly one-third of a cylinder with the same base and height.
Key rule
Cone volume is one-third of the matching cylinder's volume.
Memory hook
One-third of a cylinder's volume.