The ratio of the three interior angles of a triangle is 1:3:5, what is the largest interior angle in this triangle?
一个三角形三个内角度数比是1：3：5，这个三角形中最大的内角是多少度．
<gadget id="calculator">1 + 3 + 5</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">180 * (5/9)</gadget>
<output>100</output>

<result>100</result>