A right triangle ABC, if ∠B is 90 degrees, and ∠A is 5 times the degree of ∠C, then what is the degree of ∠A?
一个直角三角形ABC，如果∠B是90度，∠A的度数是∠C的5倍，那么∠A是多少度．
<gadget id="calculator">1 + 5</gadget>
<output>6</output>

<gadget id="calculator">90 / 6</gadget>
<output>15</output>

<gadget id="calculator">15 * 5</gadget>
<output>75</output>

<result>75</result>