Inclusion-Exclusion Principle
If 
, ..., 
are finite sets, then
where
is the sum of the Cardinalities of the intersections of the sets taken 
at a time.- Great Truncated Cuboctahedron
- Great Truncated Icosahedron
- Great Truncated Icosidodecahedron
- Grebe Point
- Greedy Algorithm
- Greek Cross
- Greek Problems
- Greene's Method
- Green's Function
- Green's Function--Helmholtz Differential Equation
- Green's Function--Poisson's Equation
- Green's Identities
- Green Space
- Green's Theorem
- Gregory Number
- Gregory's Formula
- Grelling's Paradox
- Grenz-Formel
- Griffiths Points
- Griffiths' Theorem
- Grimm's Conjecture
- Grinberg Formula
- Groemer Packing
- Groemer Theorem
- Gronwall's Theorem