The ratio of the three interior angles of a triangle is 7:5:6, what is the difference between the largest angle and the smallest angle of this triangle.
一个三角形三个内角度数比是7：5：6，这个三角形最大角与最小角相差多少度．
<gadget id="calculator">7 + 5 + 6</gadget>
<output>18</output>

<gadget id="calculator">7 / 18</gadget>
<output>7/18 = around 0.388889</output>

<gadget id="calculator">180 * (7/18)</gadget>
<output>70</output>

<gadget id="calculator">5 / 18</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">180 * (5/18)</gadget>
<output>50</output>

<gadget id="calculator">70 - 50</gadget>
<output>20</output>

<result>20</result>