Wednesday evenings from 6:30 p.m. to 7:30 p.m. on the traffic triangle at 14th St. and Ninth Ave., free classes in capoeira — a dance-like Afro-Brazilian martial art — are being offered throughout the summer. On Thursdays through Aug. 26, from 6:30 p.m. to 9 p.m., “Sunset Salsa,” a free salsa series, takes over the triangle. The first hour is salsa lessons, followed by social dancing with live DJ’s.