"Şu ev üç odalıdır." Translation: That house has three rooms.
"That house is with three rooms." - Correct other answer accepted by Duo.
Üç follows ev. When Turkish adjectives follow a noun it is stating a fact.
"Şu ev üç odalı." - Also correct & the "-dır" suffix is for emphasis & reinforces the verb. I like this - "Şu ev üç odalıdır." It sounds more reassuring.