Using Shape Options > Rounded > 0 px, the corners of shapes can be changed from rounded to sharp. This feature should be available with lines as well.
Enable Removal of Rounded Corners on Lines
Best answer by Geoff G
Hello! Great news! That feature actually is available for lines as well. Here’s a screenshot showing where you can modify this property in Lucidchart:

Thanks for posting, and please let us know if you have any other ideas for ways we can improve our products!
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