In Problems 27-40, (a) find the center (h, k) and radius r of each circle; (b) graph each circle; (c) find the intercepts, if any. 27. x² + y² = 4 2 29. 2(x − 3)² + 2y² = 8 - 31. x² + y² - 2x - 4y -4 = 0 33. x² + y² + 4x - 4y - 1 = 0