The ratio of the lengths of the three sides of a right triangle is 3:5:4. It is known that the perimeter of this right triangle is 36 cm. What is its area in square centimeters?
一个直角三角形三条边长度的比是3：5：4，已知这个直角三角形的周长36厘米，它的面积多少平方厘米？
<gadget id="calculator">3 + 5 + 4</gadget>
<output>12</output>

<gadget id="calculator">4 / 12</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 / 12</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) / 2</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">36 * (1/3) * 36 * (1/8)</gadget>
<output>54</output>

<result>54</result>