⬛ 面积计算器Area Calculator
计算矩形、三角形、圆、梯形、椭圆、平行四边形等常见图形面积。Calculate the area of rectangles, triangles, circles, trapezoids, ellipses and parallelograms.
使用说明与常见问题How-to & FAQ
「面积计算器」是什么？What is the Area Calculator tool?
计算矩形、三角形、圆、梯形、椭圆、平行四边形等常见图形面积。Calculate the area of rectangles, triangles, circles, trapezoids, ellipses and parallelograms.
如何使用「面积计算器」？How do I use the Area Calculator tool?
在「面积计算器」中，填写「形状」、「a」、「b」、「c」等参数，结果会随输入实时计算并显示在下方。In the Area Calculator: Fill in "Shape", "a", "b", "c"; results are recalculated instantly as you type.
计算精度如何？How precise are the results?
「面积计算器」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 Area Calculator uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「面积计算器」免费吗？需要注册吗？Is the Area Calculator free? Do I need an account?
「面积计算器」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 Area 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.