In an isosceles triangle, the top angle is known to be 105°, what is the base angle?
在一个等腰三角形中，已知顶角是105°，求一个底角是多少度？
<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>