Find the area of the shaded region in fig, where a circular arc of radius 6 cm has been drawn with vertex O of an equilateral triangle OAB of side 12 cm as centre.

Area of Shaded region=Area of equilateral triangle ABO + Area of Major sector
Area of Equilateral Triangle ABO = √3/4 × a² = √3/4 × 12 × 12 cm² = 62.352 cm²
Area of major sector = θ/360 × π × r² = 300/360 × π × 6 × 6 cm² = 94.2 cm²
Area of Shaded region = 62.352 + 94.2 = 156.55 cm²