The ratio of the three interior angles in a triangle is 21:31:61, what is the smallest angle in this triangle?
某三角形中三个内角度数的比是21：31：61，这个三角形中最小的角是多少度．
<gadget id="calculator">180 / 113</gadget>
<output>180/113 = around 1.59292</output>

<gadget id="calculator">(180/113) * 21</gadget>
<output>3_780/113 = around 33.451327</output>

<result>3_780/113 = around 33.451327</result>