You can also use angle ratio 30-60-90 to prove that; besides, if you times that by 6, you'll get the area of a regular hexagon.
More links on Pascal's Triangle from Art of Problem Solving:
Introducing Pascal's Triangle
Patterns in Pascal's Triangle
Other review links:
From Math is Fun
Pascal's Triangle and Its Patterns
Triangular numbers
Science link :
From NOVA : How Smart Can We Get ?
Introducing Pascal's Triangle
Patterns in Pascal's Triangle
Other review links:
From Math is Fun
Pascal's Triangle and Its Patterns
Triangular numbers
Science link :
From NOVA : How Smart Can We Get ?
