There is a cuboid iron block whose length, width, and height are 7 cm, 3 cm, and 9 cm respectively, and a cube iron block whose edge length is 5 cm, which are melted and cast into a cylinder (without loss). If the height of the cylinder is 20 cm, what is the area of its base in square centimeters?
有一个长、宽、高分别是7厘米、3厘米、9厘米的长方体铁块和一个棱长是5厘米的正方体铁块，熔铸成一个圆柱(不计损耗)．如果这个圆柱的高为20厘米，它的底面积是多少平方厘米？
<gadget id="calculator">7 * 3 * 9</gadget>
<output>189</output>

<gadget id="calculator">5 * 5 * 5</gadget>
<output>125</output>

<gadget id="calculator">189 + 125</gadget>
<output>314</output>

<gadget id="calculator">314 / 20</gadget>
<output>157/10 = around 15.7</output>

<result>157/10 = around 15.7</result>