Honestly looks less than 89 to me.

At least it's a perfect 89 degree angle

Its a perfectly drawn 89° angle...

This is not an 89° angle

More likely 87°

Don't let OP fool you, it's a circular sector.

Hey, just like my mitersaw!

I think MasterCraft's poor factory calibration is just a ploy to sell MasterCraft Digital Angle Guages.

That's it, I'm throwing my phone out of the window.

A beautiful 89/180π angle indeed.

I've never felt anything like this.

Looks like a curve connected to two lines, to me.