The A major shape barred at the 1st fret — the flat-key workhorse.
Index finger barres at the 1st fret (A-shape moved up)
Notes: A# – F – D · Formula: 1 – 3 – 5
Load B♭ Major (B♭) onto an interactive fretboard, hear every note, and build it into a progression.
Play B♭ in the Studio →A B♭ Major (B♭) chord contains the notes A#, F, D. It is built from the major formula 1 - 3 - 5, with Bb as the root.
Yes — identical pitches, identical fingering, different name. Which spelling is correct depends on the key you're in: D minor has one flat (B♭), so B♭ is the right name there. You'd only call it A♯ in a sharp key that needed it.