This cardigan is a combination of mitered square and bias stitch patterns. The cardigan is almost seamless. It means you have to seam only the sleeves side seams. The sleeves are worked first, flat using the bias stitch pattern. Then the stitches are picked up along the raglan sleeve sides and worked in short rows creating the back neckline. After that both left and right neckline stitches are connected together for the back. The back is worked in a mitered square. The front is formed by
picking up stitches on the back sides. After all the underarm stitches are joined to the front stitches the stitches are picked up along the other raglan sleeve side, then all the front stitches are worked in a bias pattern. All edges are trimmed in 1x1 ribbing.

See more pictures on Ravelry https://www.ravelry.com/patterns/library/isosceles-cardigan