i – V7– i  at the keyboard   i – V7– i for pianists William Wieland
Explanation
Simple position triads (snowmen)
Share between the hands.
Double the root of each chord.
Note that in minor keys an accidental is required to create a leading tone for the dominant seventh chord. Here it is E natural.

3 keys(Learn all 12 keys if possible.)
To play the dominant seventh chord in the right hand, use all but your middle finger. The left hand simply plays pinky - thumb - pinky.