Water, Sugar and Salt
A hexagon is a polygon that has 6 sides to it. Examples of hexagons in the real world include things such as the cells found inside of a honeycomb and a snowflake.
in the real world
Roads are an example of intersecting lines in the real world.
McDonalds Arches
On Batman(donnanonanon!)
Balls
Scales or balances.
A Jarlid
normal_distribution
The information about the theoretical tachyon particles is correct, although in the novel, they are not as theoretical as they are in the real world.
Compound interest, depreciation, bacterial growth, radioactive decay etc.
Railroad tracks, the edges of a book, and the lines on a ruled notebook paper are real-world examples of parallel lines.