As others have said, the Buddha would not have gotten angry. There are however, suttas which show his sternness such as Kucchivikara-vatthu: The Monk with Dysentery In this sutta, the Buddha and Venerable Ananda come across a very sick and neglected monk lying in his own filth in a monastery. The Buddha shows compassion and along with Ananda cleans the sick monk. But then he calls together the rest of the monks and gives them a talking to about taking responsibility for each other. While we can't know the tone the Buddha would have used; given the situation and the apparent lack of compassion shown by the monks; we can imagine it would have been stern.
The Buddha used the term "worthless man" in the Mahatanhasankhaya Sutta and others and the term "foolish man" in the Alagaddupama Sutta and others.
Of course, as an enlightened being, none of this was done in anger. The Buddha would have known the best way to speak to each to make them understand and sometimes this would not have been in a gentle tone.
There is another question on the site "Was the Buddha Harsh?""Was the Buddha Harsh?" which has many more examples of this type of necessary speech.
