Seems like you've got everything under control so far.
Now let's go on to traids of the minor scale. As you know there are three forms of the minor scale. We will use the harmonic scale for exercises but I will make referenece to the differences of the other two minor scales when they occur.
As you can imagine the properties of the scale degrees will change in the minor scale. I will use C harmonic minor for the example.
C D Eb F G Ab B(natural)
i ii' III+ iv V VI vii'
i - minor
ii' - diminished
III+ - Augmented
iv - minor
V - Major
VI - Major
vii' - diminished
The principle for building triads in the minor scale is exactly the same as it is for the Major scale. The chords will be build using intervals of thirds. And so, I want for you to build traids on the scale degrees of B minor, Ab minor, G minor and Db minor (remember we are using the harmonic minor but be prepared to tell me what differences if any that occur in the natural and melodic minor). Try to pay attention to the quality of each chord in the context of the minor scale.