Which type of rhyme is illustrated in these lines?
let the sun and wind shine
bring back what once was mine

slant

feminine

masculine

eye

Masculine rhyme.

Explanation:

These lines exemplify the 'masculine rhyme'  as it is evident that the stress here is on the final syllable i.e. "ine" in both the lines. It could be treated as the 'feminine rhyme' as the beginning is different and the latter syllables are rhyming but here, we are unable to see an extra-syllable which characterizes 'feminine rhyme'. Thus, it is the 'masculine rhyme' here which is also known as "monosyllabic rhyme" as it occurs only in the final stressed syllable. Emily Dickinson was quite famous for this rhyme which assisted her to convey her message more effectively.

Why  are they making the building?

The sentence is in the active voice.

Why is the building being made by them?

The sentence above is in the passive voice.

Hope it helps. :)