Apple Inc. is about to give two product lines much needed upgrades after the gadgets slipped into the towering shadow of the iPhone. On Tuesday, the Cupertino, California-based technology giant will take the stage in Brooklyn, New York, to unveil new Mac computers and iPad tablets. The theme of the event is “making,” and it will take place at the Brooklyn Academy of Music — both clues to how Apple plans to reignite sales of the products. Macs and iPads have larger screens and keyboards, more versatile software and typically faster processing speeds than iPhones.