需要一个适合小学生的讲解视频，可以是动画---Question Number: 13. Question Stem: 下图由正方形②和小长方形①、③拼成,求大长方形ABCD的周长. Diagram Description: * Type: Geometric diagram. * Main Elements: A large rectangle labeled ABCD. The interior of the large rectangle is divided by two vertical lines into three regions from left to right, labeled ①, ②, and ③. Region ② is a square, and regions ① and ③ are small rectangles. * Points: Vertices A, B, C, D are the corners of the large rectangle. Point E is on the top edge AD. Point F is on the bottom edge BC. * Lines: The outer boundary forms rectangle ABCD. There are two internal vertical lines separating the regions ①, ②, and ③. The first vertical line separates region ① from region ②. The second vertical line separates region ② from region ③. * Labels: The regions are labeled ①, ②, ③ inside circles within the respective regions. The vertices of the large rectangle are labeled A, B, C, D. Points E on AD and F on BC are labeled. * Dimensions: The length of the segment ED on the top edge is labeled as 6 厘米. The length of the segment BF on the bottom edge is labeled as 9 厘米. Based on the position relative to the regions, 9 厘米 represents the width of region ①, and 6 厘米 represents the width of region ③. * Relative Position: Region ① is the leftmost region, region ② is the middle region, and region ③ is the rightmost region. E is on the top edge AD, marking the boundary between region ② and ③. F is on the bottom edge BC, marking the boundary between region ① and ②. * Units: 厘米 (centimeters).