https://5993.cyberbiz.tw/s/files/5993/ckeditor/pictures/content_7129e59f-6127-4b8b-869d-9089fceecbe8.jpg The bridge is a representative building. It is not only the crystallization of the wisdom of mankind to challenge the terrain, but also the symbol of scientific progress. Among the many types of bridge technology, one of the most representative bridges is the arch bridge. https://5993.cyberbiz.tw/s/files/5993/ckeditor/pictures/content_19a80dfb-a853-4ec4-9e6c-900e932b2a78.jpg https://5993.cyberbiz.tw/s/files/5993/ckeditor/pictures/content_928f435d-8ed6-4614-a7f0-f7fa2cd645cb.jpg https://5993.cyberbiz.tw/s/files/5993/ckeditor/pictures/content_cea61591-3b33-435f-9a16-80639f24c51d.jpg The earliest purpose of building arch bridges is that it is not easy to obtain large-scale timber in some areas, or to replace wooden bridges with stone bridges because of the rigidity and durability of stones. The oldest stone arch bridge still in use is China's "Anji Bridge", which has been used for more than a thousand years. Do you know what principle the arch bridge is formed from? Mr. Sai will come to answer! The arch bridge is built using the "shape resistance principle" in mechanics, and does not require any nails and adhesives. Purely using the friction between the blocks and the force of gravity to achieve a static balance, forming a strong arch bridge, Such a subtle mechanical principle must be bought to witness the wisdom of science. This product can be rearranged by itself, increasing the durability, using dense board material, reducing wood cutting and environmental protection. At the same time, it has the advantages of easy cutting and engraving, so you can color yourself! https://5993.cyberbiz.tw/s/files/5993/ckeditor/pictures/content_81ea247c-2025-4f39-b838-891640287a06.jpg Product specifications: ► Packing size: length 34cm / width 14cm ► Material: Environmentally-friendly board (do not place in a damp environment to avoid material deformation) ► Origin: China Precautions: ► The dense board is regenerated from the wood chip combination. The irregular wood chip indentation and mottled color can be seen in the section, so the color of each building block is not the same!