You are expected to know and understand what constitutes plagiarism. Plagiarism consists of using - WITHOUT providing proper attribution - someone else's proprietary material in the form of:
Plagiarism also includes:
Copying passages from any of your course tests or materials without giving proper attribution to the author(s)
Using material from the Internet without providing proper acknowledgment to the Internet site
If you have any doubs about your understanding of what constitutes plagiarism, consult with your instructor immediately. Pleas of 'unintentional plagiarism' will have no bearing on the consequences resulting from such a violation of academic integrity.