In a right triangle, the altitude from the vertex containing the right angle cuts the hypotenuse in two segments such that the square of the altitude is equal to the product of the two segments.
If the hypotenuse = 1 , one angle is the central angle of the unit circle:
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([i]Given α, draw sin²(α), cos²(α), sin(α)cos(α)[/i] or the converse).
