前言
原生HTML+CSS+JS实现，复制即用，简单粗暴。
功能说明
通过传入直角三角形的两条边来计算剩余的边和角度 或者 一条边和一个角度。运行信息打印在控制台和textarea中。
ps：由于浮点数的精度问题，计算结果会有浮动，所以不要无脑复制了，如果输出为29.999999这种可以手算一下看看是不是30的情况
在线试用
效果图
2边求其他
1边1角求其他
源码
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
<meta name="referrer" content="no-referrer" />
<title>直角三角形边角计算</title>
<style>
table.default-table {
width: 100%;
border: solid #333;
border-width: 1px 0px 0px 1px;
font-size: #333;
border-collapse: collapse;
border-spacing: 0;
}
table.default-table tbody tr {
height: 20px;
line-height: 20px;
}
table.default-table tbody tr.odd {
background-color: #fff;
}
table.default-table tbody tr.even {
background-color: #F5F5F5;
}
table.default-table tbody tr:hover {
background-color: #eee;
}
table.default-table tbody tr th,
table.default-table tbody tr td {
padding: 3px 5px;
text-align: left;
/* border: 1px solid #ddd; */
border: solid #333;
border-width: 0px 1px 1px 0px;
}
table.default-table tbody tr th {
font-weight: bold;
text-align: center;
}
table.default-table tbody tr td.tac {
text-align: center;
}
table.default-table tbody tr td a:hover {
color: #0080c0;
}
input#c_angle {
background: gainsboro;
}
input#calculate_btn {
width: 92px;
height: 38px;
line-height: 38px;
border: 1px solid transparent;
padding: 0 18px;
background-color: #1E9FFF;
color: #fff;
white-space: nowrap;
text-align: center;
font-size: 14px;
border-radius: 2px;
cursor: pointer;
}
input#clear_btn {
width: 92px;
height: 38px;
line-height: 38px;
border: 1px solid transparent;
padding: 0 18px;
background-color: #FF5722;
color: #fff;
white-space: nowrap;
text-align: center;
font-size: 14px;
border-radius: 2px;
cursor: pointer;
}
input {
height: 38px;
line-height: 1.3;
border-width: 1px;
border-style: solid;
background-color: #fff;
color: rgba(0, 0, 0, .85);
border-radius: 2px;
font-size: 22px;
}
textarea {
width: 100%;
}
</style>
</head>
<body>
<div>
<h1>直角三角形 边长、角度计算工具</h1>
<p>说明：因为精度问题，算出的角度和长度会有一定的浮点偏差，如44.999999可以认为就是45。</p>
<svg width="327" height="278" xmlns="http://www.w3.org/2000/svg">
<g>
<title>直角三角形</title>
<line stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_1" y2="241.64704" x2="35.70585"
y1="9.64704" x1="32.70585" stroke="#000" fill="none" />
<line stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_2" y2="241.64704" x2="36.70585"
y1="242.64704" x1="299.70585" stroke="#000" fill="none" />
<line transform="rotate(-0.118927 166.372 126.147)" stroke="#000" stroke-linecap="undefined"
stroke-linejoin="undefined" id="svg_3" y2="242.31266" x2="299.37535" y1="9.98058" x1="33.36961"
fill="none" />
<rect stroke="#000" id="svg_4" height="6.33201" width="7.3318" y="235.18426" x="35.57987" fill="none" />
<text xml:space="preserve" text-anchor="start" font-family="Noto Sans JP" font-size="11"
stroke-width="0" id="svg_5" y="229.51878" x="46.2443" stroke="#000" fill="#000000">90°</text>
<text xml:space="preserve" text-anchor="start" font-family="Noto Sans JP" font-size="24"
stroke-width="0" id="svg_6" y="138.53785" x="12.25142" stroke="#000" fill="#000000">a</text>
<text xml:space="preserve" text-anchor="start" font-family="Noto Sans JP" font-size="24" id="svg_7"
y="272.17651" x="142.55744" stroke-width="0" stroke="#000" fill="#000000">b</text>
<text xml:space="preserve" text-anchor="start" font-family="Noto Sans JP" font-size="24"
stroke-width="0" id="svg_8" y="119.54184" x="173.21768" stroke="#000" fill="#000000">c</text>
<path
d="m293.85905,236.18406c0,0 -0.25668,0.00891 -0.33325,0.33325c-0.1712,0.72528 -0.80515,0.92017 -1.33307,1.99957c-0.46301,0.94672 -0.33325,1.33307 -0.99979,1.9996l0,0.6665l0,0.66653l0,0.66653"
id="svg_9" stroke-width="0" stroke="#000" fill="#000000" />
<path
d="m32.91377,19.22953c0,-0.33327 0.29378,-0.26986 1.33305,0.33326c0.64453,0.37403 1.66631,0.66653 1.99957,0.66653c0.33327,0 0.66653,0 2.33284,-0.33326l0.33327,-0.33327l0.66653,-0.99979"
id="svg_12" stroke-width="0" stroke="#000" fill="none" />
<path
d="m32.91377,19.22953c0,0 0.66652,0 0.99979,0c0.33327,0 0.43086,0.09761 0.66652,0.33326c0.23566,0.23566 0.76985,0.22079 1.66632,-0.33326c0.40092,-0.24778 1.27454,-0.69915 1.66632,-1.33305c0.17522,-0.28349 -0.10245,-0.72851 0.33327,-1.33305c0.27557,-0.38234 0.33325,-0.99979 0.33325,-1.33305l0,-0.33327"
id="svg_14" stroke-width="0" stroke="#000" fill="#000000" />
<text xml:space="preserve" text-anchor="start" font-family="Noto Sans JP" font-size="13" id="svg_15"
y="42.22471" x="36.91292" stroke-width="0" stroke="#000" fill="#000000">∠b</text>
<text xml:space="preserve" text-anchor="start" font-family="Noto Sans JP" font-size="13" id="svg_16"
y="237.5171" x="259.53292" stroke-width="0" stroke="#000" fill="#000000">∠a</text>
</g>
</svg>
</div>
<div>
<table>
<tr>
<td>
<p>a的长度</p>
</td>
<td>
<input id="a_len" type="text">
</td>
</tr>
<tr>
<td>
<p>b的长度</p>
</td>
<td>
<input id="b_len" type="text">
</td>
</tr>
<tr>
<td>
<p>c的长度</p>
</td>
<td>
<input id="c_len" type="text">
</td>
</tr>
<tr>
<td>
<p>a的角度</p>
</td>
<td>
<input id="a_angle" type="text">
</td>
</tr>
<tr>
<td>
<p>b的角度</p>
</td>
<td>
<input id="b_angle" type="text">
</td>
</tr>
<tr>
<td>
<p>c的角度</p>
</td>
<td>
<input id="c_angle" type="text" value="90" readonly="readonly">
</td>
</tr>
<tr>
<td>
<input id="calculate_btn" type="button" value="计算" onclick="calculate()">
</td>
<td>
<input id="clear_btn" type="button" value="清空" onclick="clear_input()">
</td>
</tr>
</table>
</div>
<div>
<textarea id="log_area" rows="30" cols="50" readonly="readonly"></textarea>
</div>
<script>
function calculate() {
// a b为直角边
var a_len = document.getElementById("a_len").value;
var b_len = document.getElementById("b_len").value;
var c_len = document.getElementById("c_len").value;
var a_angle = document.getElementById("a_angle").value;
var b_angle = document.getElementById("b_angle").value;
// var c_angle = document.getElementById("c_angle").value;
var temp1 = (a_angle.length > 0 ? 1 : 0) + (b_angle.length > 0 ? 1 : 0);
var temp2 = (a_len.length > 0 ? 1 : 0) + (b_len.length > 0 ? 1 : 0) + (c_len.length > 0 ? 1 : 0);
// 排除错误数据
if ((a_len.length > 0 && b_len.length == 0 && c_len.length == 0 && (temp1 == 2 || temp1 == 0)) ||
(a_len.length == 0 && b_len.length > 0 && c_len.length == 0 && (temp1 == 2 || temp1 == 0)) ||
(a_len.length == 0 && b_len.length == 0 && c_len.length > 0 && (temp1 == 2 || temp1 == 0)) ||
(a_len.length > 0 && b_len.length > 0 && c_len.length > 0)) {
console.log("数据有误，提供数据过多或过少，无法计算");
document.getElementById("log_area").prepend("数据有误，提供数据过多或过少，无法计算\n");
return;
}
// 浮点数筛查
if ((BASEisNotFloat(a_len) && a_len.length > 0) ||
(BASEisNotFloat(b_len) && b_len.length > 0) ||
(BASEisNotFloat(c_len) && c_len.length > 0)) {
console.log("数据有误，非浮点数，无法计算");
document.getElementById("log_area").prepend("数据有误，非浮点数，无法计算\n");
return;
}
if ((BASEisNotFloat(a_angle) && a_angle.length > 0) ||
(BASEisNotFloat(b_angle) && b_angle.length > 0)) {
console.log("数据有误，非浮点数，无法计算");
document.getElementById("log_area").prepend("数据有误，非浮点数，无法计算\n");
return;
}
// 角度筛查
if ((parseFloat(a_angle) >= 90 && a_angle.length > 0) ||
(parseFloat(a_angle) >= 90 && a_angle.length > 0)) {
console.log("数据有误，角度超出范围，无法计算");
document.getElementById("log_area").prepend("数据有误，角度超出范围，无法计算\n");
return;
}
var a_float = parseFloat(a_len);
var b_float = parseFloat(b_len);
var c_float = parseFloat(c_len);
if (b_float >= c_float || a_float >= c_float) {
console.log("数据有误，直角边大于等于斜边，无法计算");
document.getElementById("log_area").prepend("数据有误，直角边大于等于斜边，无法计算\n");
return;
}
var a2 = Math.pow(a_float, 2);
var b2 = Math.pow(b_float, 2);
var c2 = Math.pow(c_float, 2);
// 有2边，求1边和2角度
if(temp2 == 2) {
// 没有数据的即是要求的边
if (a_len.length == 0) {
a_float = Math.sqrt(c2 - b2);
document.getElementById("a_len").value = a_float;
} else if (b_len.length == 0) {
b_float = Math.sqrt(c2 - a2);
document.getElementById("b_len").value = b_float;
} else if (c_len.length == 0) {
c_float = Math.sqrt(a2 + b2);
document.getElementById("c_len").value = c_float;
}
var a_angle_float = Math.asin(a_float / c_float) * 180 / Math.PI;
var b_angle_float = Math.asin(b_float / c_float) * 180 / Math.PI;
document.getElementById("a_angle").value = a_angle_float;
document.getElementById("b_angle").value = b_angle_float;
}
// 有1边1角，求2边1角
else if(temp2 == 1 && temp1 == 1) {
var a_angle_float = parseFloat(document.getElementById("a_angle").value);
var b_angle_float = parseFloat(document.getElementById("b_angle").value);
// 根据不同边，选用不同公式
if(a_len.length > 0) {
// 已知a边和a角时
if(a_angle.length > 0) {
document.getElementById("b_angle").value = 90 - a_angle_float;
c_float = a_float / Math.sin(a_angle_float * Math.PI / 180);
b_float = a_float / Math.tan(a_angle_float * Math.PI / 180);
document.getElementById("c_len").value = c_float;
document.getElementById("b_len").value = b_float;
} else {
// 已知a边和b角时
document.getElementById("a_angle").value = 90 - b_angle_float;
c_float = a_float / Math.cos(b_angle_float * Math.PI / 180);
b_float = a_float * Math.tan(b_angle_float * Math.PI / 180);
document.getElementById("c_len").value = c_float;
document.getElementById("b_len").value = b_float;
}
} else if(b_len.length > 0) {
// 已知b边和a角时
if(a_angle.length > 0) {
document.getElementById("b_angle").value = 90 - a_angle_float;
c_float = b_float / Math.cos(a_angle_float * Math.PI / 180);
a_float = b_float * Math.tan(a_angle_float * Math.PI / 180);
document.getElementById("c_len").value = c_float;
document.getElementById("a_len").value = a_float;
} else {
// 已知b边和b角时
document.getElementById("a_angle").value = 90 - b_angle_float;
c_float = b_float / Math.sin(b_angle_float * Math.PI / 180);
a_float = b_float / Math.tan(b_angle_float * Math.PI / 180);
document.getElementById("c_len").value = c_float;
document.getElementById("a_len").value = a_float;
}
} else {
// 已知c边和a角时
if(a_angle.length > 0) {
document.getElementById("b_angle").value = 90 - a_angle_float;
a_float = c_float * Math.sin(a_angle_float * Math.PI / 180);
b_float = c_float * Math.cos(a_angle_float * Math.PI / 180);
document.getElementById("a_len").value = a_float;
document.getElementById("b_len").value = b_float;
} else {
// 已知c边和b角时
document.getElementById("a_angle").value = 90 - b_angle_float;
a_float = c_float * Math.cos(b_angle_float * Math.PI / 180);
b_float = c_float * Math.sin(b_angle_float * Math.PI / 180);
document.getElementById("a_len").value = a_float;
document.getElementById("b_len").value = b_float;
}
}
}
// 其他情况一律认为不合规
else {
console.log("数据有误，不予计算");
document.getElementById("log_area").prepend("数据有误，不予计算\n");
}
console.log("运行完毕");
document.getElementById("log_area").prepend("运行完毕\n");
}
// 判断是否为浮点数
function BASEisNotFloat(theFloat) {
len = theFloat.length;
dotNum = 0;
if (len == 0)
return true;
for (var i = 0; i < len; i++) {
oneNum = theFloat.substring(i, i + 1);
if (oneNum == ".")
dotNum++;
if (((oneNum < "0" || oneNum > "9") && oneNum != ".") || dotNum > 1)
return true;
}
if (len > 1 && theFloat.substring(0, 1) == "0") {
if (theFloat.substring(1, 2) != ".")
return true;
}
return false;
}
function clear_input() {
console.log("清空数据");
document.getElementById("a_len").value = "";
document.getElementById("b_len").value = "";
document.getElementById("c_len").value = "";
document.getElementById("a_angle").value = "";
document.getElementById("b_angle").value = "";
}
</script>
</body>
</html>