A partnership between New York-based developers F&T Group has opened Tangram Tower, an 85,000-square-foot office building within the Tangram mixed-use development in Queens. The building is currently 80 percent sold to medical practitioners and other professionals. Tangram Tower offers access to the 1.2 million-square-foot Tangram development’s two residential towers and hotel, as well as an array of retail and culinary options. Margulies Hoelzli Architecture designed the development.