While measuring the sides of a square ABCD, (with AB, BC, CD, and DA being its sides and, AB and CD being opposite sites and, BC and DA being opposite sides) :

1> an error of 10% in excess is made on opposite sides AB and CD, and

2> an error of 10% shortage is made on opposite sides BC and DA.

What is the error percentage in the calculated area when compared to the original area?