Use a piece of red paper with a length of 100 cm and a width of 80 cm to make some small triangular flags whose right-angled sides are 20 cm and 10 cm respectively. How many sides can you make at most?
用一张长100厘米，宽80厘米的红纸，做一些直角边分别是20厘米和10厘米的三角形小旗，最多能做多少面？
<gadget id="calculator">80 / 10</gadget>
<output>8</output>

<gadget id="calculator">100 / 20</gadget>
<output>5</output>

<gadget id="calculator">8 * 5 * 2</gadget>
<output>80</output>

<result>80</result>