Located in Columbia, Canada; the Williston Lake is one of the largest manmade lakes available. The lake build on the Peace River and covers an area of about 251 km long and 155 km wide totaling up to 1,761 square km.
An axiom or postulate is a premise or starting point of reasoning. As classically conceived, an axiom is a premise so evident as to be accepted as true without controversy.
The term  axiom may also be used to refer to a background assumption. Example of a postulate: Through any two points in a plane there is exactly one straight line. A theorem is a statement that can be proven to be true based upon postulates and previously proven theorems.