Why is Nora’s husband angry when he learns the details of what Nora’s done? And why does Nora believe that her husband should NOT be angry?
Torvald is angry because Nora has betrayed his trust with several lies. She lies to Torvald about borrowing the money, and she lies to him how she spends the "household" money and about taking odd jobs to get extra money in order to pay back the money she has borrowed. Trovald believes Nora's actions have ruined his honor, and he values honor above everything else, including love.
Nora believes that Torvald should not be angry with her because she did this to help Trovald, and she believes she is lying to protect Torvald. Her actions were out of love for him. Ironically, the same betrayal that Torvald felt from Nora, Nora felt from Trovald in the end because she cannot forgive him for not understanding why she did what she did--out of love.
Torvald is obviously upset with Nora because of her deceit and lies toward him. However, he is also angry because his public appearance has now been altered, and Nora has ruined his reputation. Nora does not think Torvald shoould be so angry because she broke the law out of love for him. The fact that he is missing this important point shows the ruined state of their relationship.