A cone with a base circumference of 12.56 cm and a height of 5 cm is formed by rotating a right-angled triangle with the right-angled side as the axis. What is the area of this right-angled triangle in square centimeters?
一个底面周长为12.56厘米，高为5厘米的圆锥是通过一个直角三角形一条，直角边为轴旋转而成的，这个直角三角形的面积是多少平方厘米？
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">2 * (5/2)</gadget>
<output>5</output>

<result>5</result>