🔺 三角形计算器Triangle Calculator
已知三条边求三角形面积（海伦公式）、周长、三个角和类型。Find triangle area (Heron's formula), perimeter, angles and type from three sides.
使用说明与常见问题How-to & FAQ
「三角形计算器」是什么？What is the Triangle Calculator tool?
已知三条边求三角形面积（海伦公式）、周长、三个角和类型。Find triangle area (Heron's formula), perimeter, angles and type from three sides.
如何使用「三角形计算器」？How do I use the Triangle Calculator tool?
在「三角形计算器」中，填写「边 a」、「边 b」、「边 c」等参数，结果会随输入实时计算并显示在下方。In the Triangle Calculator: Fill in "Side a", "Side b", "Side c"; results are recalculated instantly as you type.
计算精度如何？How precise are the results?
「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 Triangle Calculator uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「三角形计算器」免费吗？需要注册吗？Is the Triangle Calculator free? Do I need an account?
「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 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.