I'm designing a flat pattern for a folded prism cut at an angle of 45 on both ends. The metal sheet will be V-cut at the bends before being brake pressed.

The flat pattern I'm required to make should have sharp corners at the bends, so when the sheet is V-cut and bent, it will give a sharp finish. However, when I try to shape the prism (with K-factor of 0.4), I always get rounded corners. Moreover, there are some irregular extrusions on the borders which are impractical for production.

What I'm doing seems quite straight forward. I wonder what's the best way to accomplish this. I'm very new to Solidworks (2 days only) and it'd be helpful if you could give a bit more detail. Thank you!