This structure is a chiral substance as shown. If we assume that the picture represents a racemate, then it can be named

(±)-trans-1,2-dimethylcyclopropane

or

d,l-trans-1,2-dimethylcyclopropane

If it is assumed that we wish to name the single enantiomer shown, then the name would be

(R,R)-1,2-dimethylcyclopropane

Click here for help with R and S configuration.