If the measure of the apex angle of an isosceles triangle is three times the measure of the base angle, what is the measure of the apex angle?
一个等腰三角形顶角的度数是底角的度数的3倍，则顶角为多少度．
<gadget id="calculator">1 + 1 + 3</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">180 * (3/5)</gadget>
<output>108</output>

<result>108</result>