One base angle of an isosceles triangle is 60°, what is its top angle? What else could it be called a triangle?
等腰三角形的一个底角是60°，它的顶角是多少度？它还可以叫做什么三角形？
<gadget id="calculator">180 - 60 - 60</gadget>
<output>60</output>

<result>60</result>