Define the dipole moment. Why the BF₃ molecule dipolement is zero.

The product of the magnitude of the charge on any one of the poles and distance between that poles in a polar molecule is called as dipolemoment. $\mathrm{\mu }=\mathrm{\delta }\times \mathrm{d}$
The dipole moment of BF₃ molecule is zero.
Reason: The three bond moments give net sum as zero. Because the resultant of any two bonds is equal and opposite to the third bond.