A steel bar with a cross-sectional diameter of 2 cm is cut into two sections, and the sum of its surface area is 75.36 square centimeters. What is the original volume of this steel bar in cubic centimeters?
横截面直径为2厘米的一根钢筋，横截成两段后，表面积的和为75.36平方厘米，原来这根钢筋的体积是多少立方厘米？
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 10</gadget>
<output>31.4</output>

<result>31.4</result>