<p><b>十四邊形</b>是幾何學上所有含14條邊和14隻角的多邊形。
</p><p>正十四邊形的每隻內角為<span>154.<span>285714</span></span>度，是根據此公式計算：<span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle 180\times {6 \over 7}}">
  <semantics>
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        <mn>180</mn>
        <mo>×<!-- × --></mo>
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    <annotation encoding="application/x-tex">{\displaystyle 180\times {6 \over 7}}</annotation>
  </semantics></math></span></span>
</p><p>正十四邊形的面積可使用以下公式計算，當中<span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle A}">
  <semantics>
    <mrow class="MJX-TeXAtom-ORD">
      <mstyle displaystyle="true" scriptlevel="0">
        <mi>A</mi>
      </mstyle>
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    <annotation encoding="application/x-tex">{\displaystyle A}</annotation>
  </semantics></math></span></span>代表面積，<span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle a}">
  <semantics>
    <mrow class="MJX-TeXAtom-ORD">
      <mstyle displaystyle="true" scriptlevel="0">
        <mi>a</mi>
      </mstyle>
    </mrow>
    <annotation encoding="application/x-tex">{\displaystyle a}</annotation>
  </semantics></math></span></span>代表邊長。
</p><p><span><span><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle A={\frac {14}{4}}a^{2}\cot {\frac {\pi }{14}}\approx 15.3345a^{2}}">
  <semantics>
    <mrow class="MJX-TeXAtom-ORD">
      <mstyle displaystyle="true" scriptlevel="0">
        <mi>A</mi>
        <mo>=</mo>
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          <mfrac>
            <mn>14</mn>
            <mn>4</mn>
          </mfrac>
        </mrow>
        <msup>
          <mi>a</mi>
          <mrow class="MJX-TeXAtom-ORD">
            <mn>2</mn>
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        </msup>
        <mi>cot</mi>
        <mo>⁡<!-- ⁡ --></mo>
        <mrow class="MJX-TeXAtom-ORD">
          <mfrac>
            <mi>π<!-- π --></mi>
            <mn>14</mn>
          </mfrac>
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        <mo>≈<!-- ≈ --></mo>
        <mn>15.3345</mn>
        <msup>
          <mi>a</mi>
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            <mn>2</mn>
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    <annotation encoding="application/x-tex">{\displaystyle A={\frac {14}{4}}a^{2}\cot {\frac {\pi }{14}}\approx 15.3345a^{2}}</annotation>
  </semantics></math></span></span>
</p>
<h2><span id=".E5.B0.BA.E8.A7.84.E4.BD.9C.E5.9B.BE"></span><span id="尺规作图">尺規作圖</span></h2>
<p>正十四邊形不能僅用尺規作出。以下給出一個誤差為0.05°的近似作圖：

</p>
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**十四邊形**是幾何學上所有含 14 條邊和 14 隻角的多邊形。

正十四邊形的每隻內角為 154.285714 度，是根據此公式計算： $180\times {6 \over 7}$

正十四邊形的面積可使用以下公式計算，當中 $A$ 代表面積， $a$ 代表邊長。

$$
A={\frac {14}{4}}a^{2}\cot {\frac {\pi }{14}}\approx 15.3345a^{2}
$$

## 尺規作圖

正十四邊形不能僅用尺規作出。以下給出一個誤差為 0.05° 的近似作圖：
14邊形