The square root of two over two.
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The Sine of 45 degrees is the square root of 2 over 2. ChaCha on!
http://www.chacha.com/question/whatissineof45...

A forty five degree angle is one half of a right angle. And it is one equal angles of an isosceles right triangle. It is also a construction measurement for cornices.
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1. Turn on your calculator. Press the "SIN^1" or "ARCSIN" button on the calculator keypad. For example, if you have a Texas Instruments TI83, press the yellow
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