Depending on whether you want to choose a few people , or the corner of the sofa : single formula : Length: 80-95 , depth: 85-90 ; seat height: 35-42 ; dorsal height : 70-90 & nbsp; & nbsp; & nbsp ;? & nbsp; Double formula : length: 126-150 ; depth : 80-90 & nbsp; & nbsp; & nbsp; & nbsp; three of the formula : ? length : 175-196 ; depth :? 80-90 & nbsp; & nbsp; & nbsp; & nbsp; four formula : length: 232-252 ; depth 80-90 & nbsp; & nbsp; & nbsp ;?