Not sure what is special about Tan(85). Looks like a rather horrible irrational number even when squared.

I do notice though that the other two multiply to leave 1.

(Tan(25) * Tan(65) = 1 I presume atran's trig. result proves it. Is this because 25+65 =90 ? and Tan(90-x) * Tan(x) = 1 etc.)

I notice that the gap between 85 and 90 is only 5. This is one sixth of the gap from 30 to zero.

I can tell from calculating the answer that it is not going to give us a whole number or the square root of a whole number.

Any idea what you are supposed to be trying to prove?

I have noticed that the angles 85 + 30 + 65 = 180

The three angles are interior angles of a triangle. I am not sure where this leads or whether it is relevant.

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