Catic was a manufacturing engineering software commonly used in the fields of machinery, electronics, aerospace, and so on. Entity is an important concept in the software, used to represent physical entities or geometric shapes. You can create entities, draw entities, edit entities, and create attributes on entities in the software. To write arc text on a specific entity, you can follow the following steps: 1 Open the software and create a new entity. 2 Choose the Symbol tab in the entity's tool bar and add a new symbol. 3. Choose the type of symbol you want, such as "text","mark","pattern", etc. 4 Create the required text or pattern in the Symbol Editor and set its size, color, background, and other attributes. 5 Pick the text or image you want to apply to the entity and move it to the entity. 6 In the entity's tool bar, select the Symbol Setting tab and set the symbol type of the entity to "text". 7. Set the symbol style and format of the entity as needed, such as font, color, alignment, etc. 8 After setting the symbols, you can save and close the Symbol Editor. 9. Use the symbol editing tools of Catic to edit the text or pattern to the desired position and style on the entity. Through the above steps, the required arc characters can be written on the entity. It should be noted that the symbols on the Catic entity can be customized according to different needs, so it needs to be adjusted according to the specific situation.