Why does a three legged

In cross-section the burrows varied from round three inches in diameter to oval three inches high and four inches wide. It separates into three layers upon standing—a brown deposit, a clear fluid, and a frothy layer. New Word List Word List. Save This Word! Incidentally, it's always possible to rotate a wobbly four-legged stool so that it becomes stable. Position the wobbly stool so that leg A is the one that's NOT in contact with the floor, then slowly rotate it clockwise, stopping every few seconds to see if it still wobbles.

When the stool has been turned through 90 degrees, leg A will be where B was originally, B will be where C was originally, etc. So now, D has replaced A as the only leg that's not touching the floor. So, at some time during the rotation, leg A must have made contact with the floor and at a later time, leg D must have broken contact with it. Why "later"? Because if D broke contact before A made contact, we would have a situation where only two of the four legs were touching the floor, contradicting the principle of three points always being in the same plane.

All that is needed is to find the moment during the rotation when A touches the floor, and the stool should be stable, with all four legs grounded. Then again, you could just use a folded-up beermat to wedge it. In fact, I have an ontological proof that such a beermat must exist - oh all right, I'll stop.

The stool legs could be uneven in length so that they match the uneven floor. We live in a world of rectangles. Our bookcases, countertops, dressers, washers, dryers, beds, nightstands, couches and chairs — rectangles surround us.

Rectangular tables just fit more easily into this rectangular landscape. Of course, this begs the question: why did we create such a rectangular landscape? The picture of the baby boy walking is from the web site of the Physiotherapy Foundation of Canada: www.

The picture of the sofa is from Wikimedia Commons. Meerkats, small carnivoran animals that fall under the mongoose family stand in an upright stance that can be said to be a tripod stance. But, visibly they have four legs. Similarly, woodpeckers use their tail feathers to brace themselves against a tree-trunk. According to the researcher, a tripod stance does not require any energy to be stable, whereas a standing upright position requires large feet and muscle work. Also, three-limbed movement is less common.