Here, ABCD is square.

Here AC and BD are diagonals.

We know that the angles of a square are bisected by the diagonals.

∴ ∠​OBX = 45° ∵∠​ABC = 90° and BD bisects ∠​ABC​
And ∠​BOX = ∠COD = 80° … Vertically opposite angles
∴​ In ∆BOX, we have:
∠AXO = ∠OBX + ​∠BOX … Exterior angle theorem
⇒​ ∠AXO = 45° + 80° = 125°
∴ ​x =125°