If the apex angle of an isosceles triangle is 105 degrees, what is the base angle?
一个等腰三角形的顶角是105度，底角是多少度．
<gadget id="calculator">180 - 105</gadget>
<output>75</output>

<gadget id="calculator">75 / 2</gadget>
<output>75/2 = around 37.5</output>

<result>75/2 = around 37.5</result>