Math Problem Solving Help Please!?

Martha Jo, who sells ribbon at the craft shop, lost her measuring tape. She had 3 pieces of ribbon already cut and knew their lengths. The lengths of the 3 peices were 11 centimeters, 13 cm, and 17 cm. While she was waiting for the manager to bring her another measuring tape, a customer came in and ordered 19 cm of ribbon. Martha Jo used the 3 peices to measure the ribbon for the customer. How did she do this?( Hint: Draw a picture to help you). Can you explain to me how you got the answer? thx