It was know as the stock market crash or great depression
The profession that a person can rely on the information about parallel and perpendicular lines are the civil engineers. They will know if the structure of the building having perpendicular beams means that it may or may not be stable depending on the material used.
Newspapers (Wall Street Journal op-eds)
Television (Real Time With Bill Maher, Sean Hannity)
Internet (Breitbart, Infowars)
Magazines (National Enquirer, Texas Monthly)
