Tangrams!

Move any shape by dragging a black vertex or the shape itself. Spin any shape by moving its white vertex.
Move any shape by dragging a black vertex or the shape itself. Spin any shape by moving its white vertex.
Move any shape by dragging a black vertex or the shape itself. Spin any shape by moving its white vertex.
Move any shape by dragging a black vertex or the shape itself. Spin any shape by moving its white vertex.
– Tim Brzezinski

Information: Tangrams!