Depending on the size and method, defrosting a refrigerator or freezer can take anywhere from 10 minutes to a day. The most common method is to unplug the refrigerator or freezer, prop the door open and allow the ice to melt on its own. However, this method may take up to a day to defrost the appliance completely.
Circle is the locus of points equidistant from a given point, the center of the circle. The common distance from the center of the circle to its points is called radius. Thus a circle is completely defined by its center (O) and radius (R): C(O, R) = O(R) = {x: dist(O, x) = R}.
The diameter is the longest straight line which can be fitted inside a circle. It passes through the center of the circle. The distance around a circle is known as the circumference. Even though the diameter and circumference are different for different circles, the number pi remains constant: its value never changes. This is because the relationship between the circumference and diameter is always the same.