There is a triangular experimental field with a base of 250m and a height of 180m. The total annual grain yield is 4.5 tons. How many tons of grain is produced per hectare on average?
有一块底250m，高180m的三角形实验田，全年共产粮食4.5吨，平均每公顷产粮多少吨？
<gadget id="calculator">180 / 2 / 10_000</gadget>
<output>9/1_000 = around 0.009</output>

<gadget id="calculator">250 * (9/1_000)</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">4.5 / (9/4)</gadget>
<output>2</output>

<result>2</result>