For reference, check these measurements on a handbag you already own.
Measure from side to side along the base of the bag.
Measure from the top of the bag down to the base.
Measure from the front edge to the back edge, along the base of the bag.
This is the vertical length of the handle from the center high point of the handle down to the opening of the bag.
This is the total length of the strap from one end to the other.