Hi, I am not much on curved lines. I have just tried it recently.But you draw your curved line on your first piece of material and cut it then use that as a guide for the cutting of you next piece of material that you want to attach. You wouldn't have to make them all the same length. You could make the third strip longer and attach it to the fist piece. Figure out how wide you want your first strip to be and then cut it that width. You might alternate the length of the other strips so you fill in the length and width of your project. You might want to applique your strips together to get the curves effect you want.
Henri