[Solved] Let O be the centre of the circle 𝑥^2 + 𝑦^2 = 𝑟^2, where 𝑟 > \\frac{\\sqrt{5}}{2}. Suppose PQ is a chord of this circle and the equation of the line passing through P and Q is 2𝑥 + 4𝑦 = 5. If the centre of the circumcircle of the triangle OPQ lies on the line 𝑥 + 2𝑦 = 4, then the value of 𝑟 is _____ - - JEE (Advanced) 2020 Paper-2