For a couple of minutes of paper or paperboard will be able to make strenuously device that will instantly show you the centre of any circle, for example, the base of the cylinder. The secret lies in the fact that the rays arrows, encircling a circle located at an angle of 90° to each other, and a “shaft” of the arrow divides this angle in half, and it always passes through the center.
Recommend to read
FOLDING BENCH
In cramped urban apartments to find the place bulky bench is almost impossible. Well, my folded takes up very little space. In addition, it is light enough to carry in the summer the...
EQUIPMENT FOR A SWIMMER
A boat with a rower moves much faster than a swimming person, even with fins, although the drag force is three or even four times greater. The efficiency of oars is higher than that of...
