Image copyright @PennridgeReform Image caption Parents complained to the school about the question

A US secondary school has apologised after setting a maths questions that asked students about a girl being sexually abused by family members.

The homework asked: "Angelou was sexually abused by her mother's _______ at age 8, which shaped her career choices and motivation for writing."

Pupils in Perkasie, Pennsylvania, were given an algebra formula with the assignment to solve the problem.

Parents complained to Pennridge High School officials about the homework.

A subsequent question in the same homework asked about a single mother who is trying to support her son by working as a pimp and a prostitute.

It asked what was her other means of support, including another formula for the options, bookie, drug dealer and nightclub dancer.

The questions were based on the life of the famed American poet Maya Angelou, but many parents complained the subject matter was not appropriate for young teenagers or a maths equation.

The same assignment surfaced two years ago in a Florida school, sparking similar controversy.

Image copyright @stephariffic

Pennridge School District said it had received a number of complaints about homework "which contained adult content without a proper context".

"The homework worksheet in question was downloaded from a website that allows teachers around the world to share educational resources.

"It is not part of our approve curriculum."

But a Twitter user, @PennridgeReform, who tweeted an image of the assignment, commented: "How can we trust the teacher with the kids' education when these questions are permitted?"