The perimeter of a right triangle is 36 cm, the ratio of the two sides is 3:4, the length of the hypotenuse is 15 cm, what is the height of the hypotenuse in cm.
一个直角三角形的周长是36厘米，两条直角边的比是3：4，斜边长15厘米，斜边上的高是多少厘米．
<gadget id="calculator">36 - 15</gadget>
<output>21</output>

<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">21 * (3/7)</gadget>
<output>9</output>

<gadget id="calculator">21 - 9</gadget>
<output>12</output>

<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">12 * (9/2) * (2/15)</gadget>
<output>36/5 = around 7.2</output>

<result>36/5 = around 7.2</result>