There are two answers, 29 and 4. If you only consider the flag surface, it is four, and if you count the pattern, it is 29. Five stars have five angles, five times five equals 25, and the four corners of the flag rectangle are exactly 29 angles.

The national flag of the people of China is a five-star red flag with a red face and an aspect ratio of 3:2. There are five yellow five-pointed stars on the upper left, and four small stars are arched on the right side of a big star, each with a corner pointing directly at the center of the big star. 1, four yellow stars, two or three yellow stars. "Historical Records of the Heavenly Palace": "The five stars are divided into the sky, accumulated in the east, and beneficial to China; Western accumulation, foreign users (soldiers) benefit. The five stars are all gathered in one room from the stars, and the country that gives up can pass through the world. "