It takes four of those little squares -- each one 1/2 inch on a side -- to cover one square inch. That's because each one is 1/2 x 1/2, or 1/4 of a square inch. In a rectangle that is 48 inches by 48 inches, there are 2304 square inches.(1 ft = 12 inches) Since it takes 4 little squares to cover 1 sq inch, then it would need 2304 x 4 squares (1/2 inch on a side each) to cover a rectangle 4 feet by 4 feet.
The stability triangle is used to describe the movement of center of gravity of a load vehicle like trucks. If the load is not balanced then it moves and may tip over it.
If you were to raise a lift truck up and look at its underside, you would see that the support points for the truck are located at points A, B, and C. The triangle formed between points A, B, and C is called the Stability Triangle. The lift truck will not tip over as long as the center of gravity remains inside the triangle.
The center of gravity is the point within a lift truck where there is equal weight all around it.