A teacher at West Boca Raton High School is under investigation after school district officials learned about risqué photos of her on a Web site. Erica Chevillar, 25, is a first-year social studies teacher at the school. She is also one of about 80 models featured on the Web site of the USA National Bikini team, a Boca Raton-based company, according to the Web site. The site lists calendars for sale featuring scantily clad models dressed in bathing suits, provocative outfits or lingerie.