Hello @CircleCreaitve, so the best way to do this is by using clip path or depending on what you are using it with an svg graphic, however there is a hacky way to do it, by using a triangle and an oval inside a div with some negative margin. kind of like this:
so the triangle is just a 100X100 div with top and bottom 50 transparent borders, and a 100 yellow solid right border. the oval is just a 20X100 div with a 50%radius. I hope this helps.