What does a red triangle mean in boating?

If you're boating through a wide channel and you see a red triangle sign on your right, take note of it, because it's telling ...
The Forward

Trump’s Nazi triangle post the latest in a series of seeming dog whistles

A red triangle. The number 14. The number 88. President Trump has again provided fodder for the critics who have accused him of using Nazi and anti-Semitic symbols to signal his sympathies with white ...
Jewish Telegraphic Agency

Red triangle, symbol associated with Hamas, is painted on Pittsburgh synagogue building

Vandals painted a symbol associated with Hamas on a synagogue in Pittsburgh, near the site of the deadliest attack on Jews in U.S. history. The slogan “Jews for Palestine” and an inverted red triangle ...
SpaceNews

Red triangle with skull and crossbones is for danger – new UN radiation symbol

A skull and crossbones, a running person and radiating ionizing waves, all on a deep red triangle, joined other more common warning symbols today as part of a United Nations effort to reduce needless ...