School officials say the Corner High School teacher apparently was teaching his students about parallel lines and angles and used the example of where to stand and aim to shoot the president.
Authorities were alerted, and Roy Sexton, special agent in charge of Birmingham's Secret Service office, says his agency spoke with the teacher, did not find a credible threat and closed the investigation. No charges were filed.
Superintendent Phil Hammonds says the teacher remains at work and there are no plans to fire him.
The teacher was apparently teaching his geometry students about parallel lines and angles, officials said, according to the Birmingham News. He used the example of where to stand and aim if shooting Mr. Obama.
"He was talking about angles and said, 'If you're in this building, you would need to take this angle to shoot the president,'" said Joseph Brown, a senior in the geometry class, the newspaper reported.
Efforts by the Birmingham News to reach the teacher for comment were unsuccessful.
Caroline Polk, the parent of a ninth-grader at the school, told the Birmingham News she doesn't believe the teacher should be fired.
"We all make mistakes, and we should be able to learn from our mistakes," she told the News. "What he said was just wrong and inappropriate. Everyone's got their own opinions, but we have to be aware of our surroundings. At this point, it just needs to be handled in a way that it won't be repeated."