檢視模式三角形的原始碼

[[分類:三角形]]
===邊長 5,7,8===
<table class=nicetable>
<tr><th colspan=3><img src='https://upload.wikimedia.org/wikipedia/commons/e/e6/Triangle-5_7_8.svg'/></th></tr>
<tr><th>1</th><th>三邊</th><td>5,7,8(右,左,底)</td></tr>
<tr><th>2</th><th>三角</th><td>60°,38.2°,81.8°(右,左,頂)</td></tr>
<tr><th>3</th><th>周長</th><td>20</td></tr>
<tr><th>4</th><th>面積</th><td>√<span style='text-decoration:overline'>300</span>≅17.32</td></tr>
<tr><th>5</th><th>内切圓<br/>半徑</th><td>1.732≅√<span style='text-decoration:overline'>3</span></td></tr>
<tr><th>6</th><th>外接圓<br/>半徑</th><td>4.04≅4</td></tr>
<tr><th>7</th><th>三中線長</th><td>7.09,5.68,4.58(中點:5,7,8)</td></tr>
<tr><th>8</th><th>三高</th><td>6.93,4.95,'''4.33'''(右,左,底)</td></tr>
<tr><th>9</th><th>底邊垂足</th><td>'''2.5'''/5.5(右,左)</td></tr>
</table>

===三角 40°,65°,75°===
<table class=nicetable>
<tr><th colspan=3><img src='https://upload.wikimedia.org/wikipedia/commons/2/27/Triangle-40°_65°_75°.svg'/></th></tr>
<tr><th>1</th><th>三邊</th><td>5,7,7.5(右,左,底)</td></tr>
<tr><th>2</th><th>三角</th><td>65°,40°,75°(右,左,頂)</td></tr>
<tr><th>3</th><th>周長</th><td>19.5</td></tr>
<tr><th>4</th><th>面積</th><td>√<span style='text-decoration:overline'>286.55859375</span>≅16.928</td></tr>
<tr><th>5</th><th>内切圓<br/>半徑</th><td>1.7362</td></tr>
<tr><th>6</th><th>外接圓<br/>半徑</th><td>3.88</td></tr>
<tr><th>7</th><th>三中線長</th><td>6.81,5.33,4.79(中點:5,7,7.5)</td></tr>
<tr><th>8</th><th>三高</th><td>6.77,4.84,'''4.51'''(右,左,底)</td></tr>
<tr><th>9</th><th>底邊垂足</th><td>'''2.1'''/5.4(右,左)</td></tr>
</table>

===三角 50°,60°,70°===
<table class=nicetable>
<tr><th colspan=3><img src='https://upload.wikimedia.org/wikipedia/commons/a/a7/Triangle-50-60-70.svg'/></th></tr>
<tr><th>1</th><th>三邊</th><td>100,113,123(右,左,底)<br/>5,5.65,6.15</td></tr>
<tr><th>2</th><th>三角</th><td>60°,50°,70°(右,左,頂)</td></tr>
<tr><th>3</th><th>周長</th><td>16.8</td></tr>
<tr><th>4</th><th>面積</th><td>√<span style='text-decoration:overline'>176.715</span>≅13.29</td></tr>
<tr><th>5</th><th>内切圓<br/>半徑</th><td>1.58</td></tr>
<tr><th>6</th><th>外接圓<br/>半徑</th><td>3.27</td></tr>
<tr><th>7</th><th>三中線長</th><td>5.35,4.84,4.36(中點:5,5.65,6.15)</td></tr>
<tr><th>8</th><th>三高</th><td>5.32,4.71,'''4.42'''(右,左,底)</td></tr>
<tr><th>9</th><th>底邊垂足</th><td>'''2.5'''/3.65(右,左)</td></tr>
</table>

===公式===
<table class=nicetable>
<tr><th colspan=3><img src='https://upload.wikimedia.org/wikipedia/commons/e/e6/Triangle-5_7_8.svg'/></th></tr>
<tr><th>1</th><th>三邊</th><td>a,b,c</td></tr>
<tr><th>2</th><th>三角</th><td>餘弦公式</td></tr>
<tr><th>3</th><th>周長</th><td>a+b+c,s=½(a+b+c)</td></tr>
<tr><th>4</th><th>面積</th><td>△ = √<span style='text-decoration:overline'>s(s-a)(s-b)(s-c)</span></td></tr>
<tr><th>5</th><th>内切圓<br/>半徑</th><td>△ = rs</td></tr>
<tr><th>6</th><th>外接圓<br/>半徑</th><td>△ = abc/4R</td></tr>
<tr><th>7</th><th>三中線長</th><td>a<sup>2</sup>+b<sup>2</sup> = 2(c/2)<sup>2</sup>+M<sub>c</sub><sup>2</sup></td></tr>
<tr><th>8</th><th>三高</th><td>△ = ½ c×h<sub>c</sub></td></tr>
</table>