Kim Kardashian [1] joined her younger sisters, Kendall Jenner and birthday girl Kylie Jenner, at the Teen Choice Awards on Sunday. Kylie, who turned 17 on Sunday, wore a similar style to Kim's, with both of them sporting crop tops and printed skirts. Meanwhile, choice hottie nominee [2] Kendall looked white hot in pants and a draped top, posing alongside her sisters on the red carpet. Earlier in the day, Kim took to Instagram [3] to post several throwback pictures of Kylie for her birthday, and Kylie shared a photo [4] of herself and her friends wearing hats with her face on them. They have another reason to celebrate, too — their show, Keeping Up With the Kardashians, won choice reality show. Take a look at the best pictures of the sisters, and then check out all the celebrities at the Teen Choice Awards [5]!