📐 勾股定理Pythagorean Theorem

使用说明与常见问题How-to & FAQ

「勾股定理」是什么？What is the Pythagorean Theorem tool?

求直角三角形未知边。本地处理。可设置「求」、「边 a」、「边 b」、「斜边 c」。Solve the unknown side of a right triangle. Processed locally. Settings: Solve for, Leg a, Leg b, Hypotenuse c.

如何使用「勾股定理」？How do I use the Pythagorean Theorem tool?

在「勾股定理」中，填写「求」、「边 a」、「边 b」、「斜边 c」等参数，结果会随输入实时计算并显示在下方。In the Pythagorean Theorem: Fill in "Solve for", "Leg a", "Leg b", "Hypotenuse c"; results are recalculated instantly as you type.

能算三维的勾股吗？Does it work in 3D?

本页只解直角三角形的一边：c² = a² + b²。三维中长方体的空间对角线是 √(a² + b² + c²)，两点距离可以用欧氏距离计算器（支持三维）。This page solves one side of a right triangle: c² = a² + b². In 3D a box's space diagonal is √(a² + b² + c²); for the distance between two points use the Euclidean distance calculator, which supports 3D.

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

例如在「勾股定理」中填 求 = 斜边 c，边 a = 3，边 b = 4，结果区显示：斜边 c：5For example, entering Leg a = 3, Leg b = 4 in the Pythagorean Theorem gives: Hypotenuse c: 5

哪些输入会被检查？Which inputs are validated?

「勾股定理」会检查这些输入——「边 a」、「边 b」、「斜边 c」：必须填写，须大于 0；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 Pythagorean Theorem checks its inputs — "Leg a", "Leg b", "Hypotenuse c": required, must be greater than 0; 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?

「勾股定理」的设置：「求」可选 斜边 c、直角边 a（默认 斜边 c）；「边 a」默认 3；「边 b」默认 4；「斜边 c」默认 5。每次生成结果都按当前设置处理。Settings in the Pythagorean Theorem — "Solve for": 2 choices; "Leg a" default 3; "Leg b" default 4; "Hypotenuse c" default 5. The result always uses the current settings.

计算精度如何？How precise are the results?

「勾股定理」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 Pythagorean Theorem uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.

「勾股定理」免费吗？需要注册吗？Is the Pythagorean Theorem free? Do I need an account?

「勾股定理」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 Pythagorean Theorem is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.