Why is a straight line 180 degrees?

Answer 1

A straight line is defined as an angle of 180 degrees because it represents a half-turn around a point. In geometric terms, if you have a point and draw two rays emanating from it in opposite directions, the angle formed between these two rays measures 180 degrees. This is based on the full circle being 360 degrees, where a straight line corresponds to half of that total. Thus, the angle formed by a straight line is precisely half of a complete rotation.