The measure ratio of the apex and base angles of an isosceles right triangle is 2:1, what is the base angle of this isosceles right triangle?
一个等腰直角三角形顶角和底角的度数比为2：1，这个等腰直角三角形的底角是多少度．
<gadget id="calculator">180 - 90</gadget>
<output>90</output>

<gadget id="calculator">90 / 2</gadget>
<output>45</output>

<result>45</result>