2024/09/18　ユニットサークル

私は、単位円　という言い方が嫌いだ。
単位　という言葉が、意味を宿しすぎている。
半径1の円だから、壱の円とでもいえばいいのに、たぶん、英語の　unit　circle　をそのまま訳して、それが権威となってしまってもう変えられないんだろう。

The term "unit circle" is not related to any specific unit; it simply refers to a circle with a radius of 1. The word "unit" means "one," but in this context, it only denotes the numerical value 1 and is not associated with any particular physical unit or measurement system.

Actually, the area and circumference of the unit circle are as follows:

• Area: The area of a circle with radius 1 is given by the formula (π r^2). Since the radius (r) is 1, the area is (π1^2 = π).

• Circumference: The circumference is given by the formula (2 πr). With a radius (r) of 1, the circumference is (2 π✕1 = 2 π).

So, the area of the unit circle is π, and the circumference is 2π