# Trigonometric Values?

Geometry Level 4

$\large \ \cos^{2} 73^{\circ} \ + \ \cos^{2} 47^{\circ} \ + \ \cos 73^{\circ} \cos 47^{\circ}$

If the value of the above expression is equal to $\dfrac {a}{b}$, where $a$ and $b$ are coprime positive integers, find $a+b$.

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