Mitre a 120mm Height Upstand

[Door7000]

I need to mitre 5 corners (4 internal, 1 external) for a 120mm by 19mm upstand that has a rounded top front edge.

I tried a test piece with a saw but the cut was not good enough. I could probably get away with the internal corners but I just know the external one will look crap.

What's the best way to cut this? Keep practicing with the saw? Use a jigsaw and homemade mitre jig? Circular saw with 45% angle?

 

[gregers]

well you could either very carefully make up a mitre box out of some scrap timber,or hire a chopsaw.