The perimeter of a right triangle is 60 cm. The ratio of the lengths of the three sides of this triangle is 3:4:5. What is the area of this triangle?
一个直角三角形的周长是60厘米，这个三角形的三条边长度之比是3：4：5，这个三角形的面积是多少？
<gadget id="calculator">3 + 4 + 5</gadget>
<output>12</output>

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

<gadget id="calculator">60 * (1/4)</gadget>
<output>15</output>

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

<gadget id="calculator">60 * (1/3)</gadget>
<output>20</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">15 * 10</gadget>
<output>150</output>

<result>150</result>