In a right triangle, the smallest angle is (1/5) of the other acute angle. What is the smallest angle?
在一个直角三角形中，最小角度数是另一个锐角度数的(1/5)，最小角是多少度．
<gadget id="calculator">180 - 90</gadget>
<output>90</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">90 / (6/5)</gadget>
<output>75</output>

<gadget id="calculator">90 - 75</gadget>
<output>15</output>

<result>15</result>