🔺 等边三角形计算器Equilateral Triangle Calculator
已知等边三角形的边长、高、面积、周长、内切圆或外接圆半径中的任意一个，求出其余所有量。Give any one of an equilateral triangle's side, height, area, perimeter, inradius or circumradius and get all the others.
使用说明与常见问题How-to & FAQ
「等边三角形计算器」是什么？What is the Equilateral Triangle Calculator tool?
已知等边三角形的边长、高、面积、周长、内切圆或外接圆半径中的任意一个，求出其余所有量。Give any one of an equilateral triangle's side, height, area, perimeter, inradius or circumradius and get all the others.
如何使用「等边三角形计算器」？How do I use the Equilateral Triangle Calculator tool?
在「等边三角形计算器」中，填写「已知量」、「数值」等参数，结果会随输入实时计算并显示在下方。In the Equilateral Triangle Calculator: Fill in "Known value", "Value"; results are recalculated instantly as you type.
等边三角形公式？Equilateral triangle formulas?
边长为 a：高 h = (√3/2)a，面积 = (√3/4)a²，周长 = 3a，内切圆半径 r = a/(2√3)，外接圆半径 R = a/√3 = 2r。With side a: height h = (√3/2)a, area = (√3/4)a², perimeter = 3a, inradius r = a/(2√3), circumradius R = a/√3 = 2r.
单位怎么处理？What about units?
结果与输入使用相同的长度单位，面积为该单位的平方。Results use the same length unit as the input; area is in that unit squared.
计算精度如何？How precise are the results?
「等边三角形计算器」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 Equilateral Triangle Calculator uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「等边三角形计算器」免费吗？需要注册吗？Is the Equilateral Triangle Calculator free? Do I need an account?
「等边三角形计算器」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 Equilateral Triangle Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.