Klu, which would prevent the collapse of the structure and the shape is a triangle-shaped base, with the strength we have to search for a host of concepts that the trapezoid is a combination of a rectangular shape.
Ourselves, which would prevent the collapse of the structure and triangular shaped base is strong, we have the concept that a combination of trapezoidal shape.
Group, we have the concept that is a combination between trapezoidal square shape, which will prevent the collapse of the structure and shape of the triangle is basic shapes with strength.