Explain why the tangent of 45° always equals 1

Draw the triangle and you will see that a = b. The tangent of 45 degrees is when both the opposite and adjacent sides of the 45-degree angle at origin are equal. ... A line at 45 degrees to the x-axis is also at 45 degrees to the y-axis because 45 degrees bisects the 90-degree angle between the two axes.
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