In a right triangle, the larger acute angle is four times the smaller acute angle, what is the smaller acute angle?
在一个直角三角形中，较大的锐角是较小的锐角的4倍，较小的锐角是多少度？
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

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

<gadget id="calculator">90 * (1/5)</gadget>
<output>18</output>

<result>18</result>