three equal forces each of value 1N acts along the side BC, CD, DE of a regular hexagon ABCDEF. Calculate the magnitude of their resultant.

Dear student,

If the vectors are joined head of one to the tail of the other, the resultant vector of such vectors is the vector with its tail at the tail of the first vector and head at the head of the last vector.

Hence, in this case, the resultant vector has head at E and tail at B. Thus the magnitude of the vector is the length of side BE, assuming that one side of the hexagon measures 1 unit. From simple geometry, answer is 2N.