Take a square piece of paper. Fold the paper in half and then open. Cut the paper in half along this crease.
With one of the triangles, fold in half and open.
Fold the top corner downwards to meet the bottom edge of the triangle.
Fold the two bottom corners upwards to meet together in the middle.
Fold the bottom corner up to the centre and then turn the model over.
Your sail boat is ready.
