Answer
$W=\vec F \cdot \vec D$
Work Step by Step
By definition, the work $W$ done by a force $\vec F$ in moving an object along a vector $\vec D$ is a scalar equals to the product of the moving distance and the component of the force along that distance, this in turn equals to the dot product of the two vectors, so that $W=\vec F \cdot \vec D$
