The surprising real ages of actors when they were cast in famous teenage roles

Age is but a number, and you don't have to be a teenager to play one on TV or film.

While some actors are closer in age to their character counterparts, others can be two or even 15 years older than the characters they portray.

Here are 11 celebrities who are well-known for their teen roles, even though they weren't teens at the time.

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Troian Bellisario plays Spencer Hastings on "Pretty Little Liars," an 18-year-old high school student.

In real life, Bellisario is 29. She was 24 when she was cast as the high-school junior. The characters graduated in the mid-season finale, and when the series returns in January, it's jumping ahead five years.

Also 0f note: Sasha Pieterse, who plays Alison DiLaurentis, is 19, so when the show returns, she'll be playing an older character.

Minka Kelly played high-school cheerleader Lyla Garrity in "Friday Night Lights."

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