A point O is the centre of a circle circumscribed about a triangle ABC. Then ABC  OA→sin⁡2A+OB→sin⁡2B +OC→sin⁡2C is equal to

The position vector of the point O with respect to itself isOA→sin⁡2A+OB→sin⁡2B+OC→sin⁡2Csin⁡2A+sin⁡2B+sin⁡2C⇒OA→sin⁡2A+OB→sin⁡2B+OC→sin⁡2Csin⁡2A+sin⁡2B+sin⁡2C=0→ or OA→sin⁡2A+OB→sin⁡2B+OC→sin⁡2C=0→