After winning against the New York Jets for the first time in the New York Area, the Green Bay Packers took on the lowly Dallas Cowboys. After a scoreless first quarter, the Packers offense that was limited to 9 points against the New York Jets, built a 28-0 lead before the Cowboys scored their only touchdown before the end of the first half. The Packers would score 17 more points in the second half before closing the game out 45-7 over the Dallas Cowboys. The Green Bay Packers intercepted Jon Kitna 3 times including one to Clay Matthews which would result in 62-yard touchdown, while Aaron Rodgers threw for 3 touchdowns. With the win, the Packers improved to 6-3.
Question: How many points ahead were the Packers at the end of the first half?
Answer: 21