# Triangle of given area

**Geometry**Level 3

Let \(PQR\) be a triangle of area \( \Delta \) with \(a = 2, b = \frac{7}{2}\) and \(c = \frac{5}{2}\), where \(a, b\) and \(c\) are the lengths of the sides of the triangle opposite to the angles at \(P, Q\) and \(R\) respectively. Then \(\frac{ 2 sin P - sin 2 P}{ 2 sin P + sin 2 P} \) equals