In a right triangle, the degree of one acute angle is (1/2) of the other acute angle, what is the smaller angle?
一个直角三角形中，一个锐角的度数是另一个锐角的(1/2)，较小角是多少．
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">90 / 3</gadget>
<output>30</output>

<result>30</result>