Answer:
√2 / 2
Step-by-step explanation:
If you draw a right triangle with sides = 1, then by Pythagoras the diagonal is sqrt(2). The angles are 45, 45, and 90. Sine = Opposite / Hypotenuse So sin 45 = 1 / sqrt(2). To eliminate the square root in the denominator, multiply numerator and denominator by sqrt(2).
This leaves it unchanged since sqrt(2) / sqrt(2) = 1. So sin 45 = sqrt(2)/2.
