def triangle(tri, draw)
      use_cairo do |cc|
        cc.triangle(tri.x1, tri.y1, tri.x2, tri.y2, tri.x3, tri.y3)
        cc.fill_n_stroke(draw)
      end
    end
def triangle(tri, draw)
      use_cairo do |cc|
        cc.triangle(tri.x1, tri.y1, tri.x2, tri.y2, tri.x3, tri.y3)
        cc.fill_n_stroke(draw)
      end
    end
:nodoc:
 @api private