Two circles with radius 2R and √2R intersect each other at points A a...
Let us draw the diagram according to the given info,
We can see that AD = A0*cos60° = 2R* 1/2 = R
In triangle, ACD
=>sinACD = AC/AC
=>sinACD = R/√2 * R = 1/√2
=>∠ACD = 45°
By symmetry we can say that ∠BCD = 45°
Therefore we can say that ∠ACB = 90°
Hence, the area colored by green color = 270°/360° * π * (√2R)2 = 3/2 * π * R2... (1)
Area of triangle ACB = 1/2 * R* 2R = R2... (2)
Area shown in blue color = 60°/360° *π* (2R)2-√3/4 * (2R)2 = 2/3 *π* R2-√3 * R2... (3)
By adding (1) + (2) + (3)
Therefore, the area of the common region between two circles = 3/2 * π * R2 + R2 + 2/3 * π * R2 - √3 * R2
=> (13π/6 + 1 +√3)R2Hence, option C is the correct answer.