President Obama can now enjoy the Cape and Islands without actually having to go there. That’s because the Whitney Museum of American Art has loaned the White House two Edward Hopper paintings done on Cape Cod in the 1930s. The paintings — “Burly Cobb’s House, South Truro” and “Cobb’s Barns, South Truro” — were installed in the Oval Office last week. Hopper, who’s known primarily for oil paintings of urban life and American landscapes, began spending summers in South Truro in 1930, and eventually built a house of his own design there in 1934. For his part, Obama and his family have spent a few weeks on Martha’s Vineyard during four of the past five summers.