Hard tangrams sprawl. Silhouettes at this tier are long, angular, and deliberately deceptive — pieces sit at unexpected rotations, the parallelogram often needs its mirrored side, and large flat regions can be assembled two or three plausible ways of which only one leaves the remaining pieces a home.
Solve the constrained extremities first and leave the big open middle for the large triangles. If you are new to the game, warm up on the daily puzzle — the daily rotates through every difficulty across the week.