A cuboid iron block with a length of 7 cm, a width of 6 cm, and a height of 4.5 cm and a square iron block with a side length of 5 cm are melted and cast into a large cylinder. The bottom area of this cylinder is 78.5 square centimeters. How many centimeters should the height be?
把一个长7厘米，宽6厘米，高4.5厘米的长方体铁块和一个棱长5厘米的正方体的铁块，熔铸成一个大圆柱体，这个圆柱体的底面积是78.5平方厘米，那圆柱的高应是多少厘米？
<gadget id="calculator">7 * 6 * 4.5</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 / 78.5</gadget>
<output>4</output>

<result>4</result>