Some people cringe at that skill. With proper cutting and accurate seam allowance, it's not that bad. You have to get around a turn in your straight line. This can be done!
So I have the diamonds ready to be attached into twos. There will be four sets of these.
The triangle will be set in the right side of each set.
Tip: sew the white part a smidge extended beyond the colored piece.
When it's ironed, you won't have dark shadows showing past the white seam.