As shown in the figure, it is known that the radius of the circle on the bottom of the cylinder is 2 π & nbsp; cm, and the height is 2cm. AB and CD are the diameters of the two bottom surfaces respectively, and AD and BC are the generatrix. If a bug starts from point a and crawls from the side to point C, the shortest length of the crawling path is______ &Nbsp; cm

As shown in the figure, it is known that the radius of the circle on the bottom of the cylinder is 2 π & nbsp; cm, and the height is 2cm. AB and CD are the diameters of the two bottom surfaces respectively, and AD and BC are the generatrix. If a bug starts from point a and crawls from the side to point C, the shortest length of the crawling path is______ &Nbsp; cm

As shown in the figure, the length of line segment AC1 in the expanded side view of the cylinder is the required length. In RT △ ab1c1, Ab1 = π· 2, π = 2 & nbsp; cm, b1c1 = 2 & nbsp; cm, AC1 = 22 & nbsp; cm, so the answer is 22