The ratio of the three interior angles of a triangle is 4:5:6, what is the measure of the largest angle in this triangle.
一个三角形的三个内角度数的比是4：5：6，这个三角形中最大角的度数是多少．
<gadget id="calculator">4 + 5 + 6</gadget>
<output>15</output>

<gadget id="calculator">6 / 15</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">180 * (2/5)</gadget>
<output>72</output>

<result>72</result>