📏 线段长度Length of a Line Segment

使用说明与常见问题How-to & FAQ

「线段长度」是什么？What is the Length of a Line Segment tool?

平面两点距离 √((x₂-x₁)²+(y₂-y₁)²)。本地处理。可设置「x₁」、「y₁」、「x₂」、「y₂」。Plane distance √((x₂-x₁)²+(y₂-y₁)²). Processed locally. Settings: x₁, y₁, x₂, y₂.

如何使用「线段长度」？How do I use the Length of a Line Segment tool?

填写两个端点的坐标 x₁、y₁、x₂、y₂，即可得到线段长度 √((x₂−x₁)² + (y₂−y₁)²)。结果会随输入实时更新。Enter the end points x₁, y₁, x₂ and y₂ to get the segment length √((x₂−x₁)² + (y₂−y₁)²). The result updates as you type.

3D？3D?

见 euclidean-distance-calculator。See euclidean-distance-calculator.

能举个计算实例吗？Can you show a worked example?

例如在「线段长度」中填 x₁ = 0，y₁ = 0，x₂ = 3，y₂ = 4，结果区显示：长度：5For example, entering x₁ = 0, y₁ = 0, x₂ = 3, y₂ = 4 in the Length of a Line Segment gives: Length: 5

哪些输入会被检查？Which inputs are validated?

「线段长度」会检查这些输入——「x₁」、「y₁」、「x₂」、「y₂」：必须填写；绝对值超过 10¹⁵ 的数也会被拒绝。不符合时结果区显示具体提示，不会给出数字。The Length of a Line Segment checks its inputs — "x₁", "y₁", "x₂", "y₂": required; numbers above 10¹⁵ in absolute value are rejected too. When a value fails, the result area names the problem instead of showing a number.

有哪些选项可以调整？What options can I adjust?

「线段长度」的设置：「x₁」默认 0；「y₁」默认 0；「x₂」默认 3；「y₂」默认 4。每次生成结果都按当前设置处理。Settings in the Length of a Line Segment — "x₁" default 0; "y₁" default 0; "x₂" default 3; "y₂" default 4. The result always uses the current settings.

计算精度如何？How precise are the results?

「线段长度」使用 JavaScript 双精度浮点数（约 15–16 位有效数字）；极大或极小的数值可能存在精度误差。The Length of a Line Segment uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.

「线段长度」免费吗？需要注册吗？Is the Length of a Line Segment free? Do I need an account?

「线段长度」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Length of a Line Segment is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.