APL (Dyalog Extended), 45 bytes

+/×{+/{a b c←⍵⋄√(×/a÷b c)+2-(⊢+÷)b÷c}¨⌽∘⍵¨⍳3}

Try it online!

Bubbler has a 27 byte solution with a complete train, but I think it deserves it's own answer.

This is a port of Surculose Suptum's formula, simplified by Kevin Cruijssen.

APL (Dyalog Extended), ⁴⁵ 44 bytes

+/×{+/{a b c←⍵⋄√(a×a÷b×c)+2-(⊢+÷)b÷c}⌽∘⍵¨⍳3}

Try it online!

Bubbler has a 27 byte solution with a complete train, but I think it deserves it's own answer.

This is a port of Surculose Suptum's formula, simplified by Kevin Cruijssen.

-1 byte from dzaima.