You've probably heard of circumference, circle and sphere, but do you know how to differentiate them? If I asked you to draw each of these three items, what would each of them look like? In the image above, there are examples of all three, but which one represents a circumference, a circle and a sphere? Let's talk a little about each one and you'll never be confused again!
THE circumference is a flat geometric figure formed by numerous points whose union results in a closed line and which are at the same distance from a central point. Imagine a compass, if you stick the metal end of the compass on paper and rotate the graphite end around the metal end, you will draw a circumference. You can get the same result if, for example, you look at a bicycle tire. The tire of any bicycle is shaped like a circumference. Each piece that makes it up is at the same distance from the tire's axle, that central place where the tire's spokes meet. Including, in a circle, we call for lightning the distance between the edge of the circle and its center.
Bicycle tires are examples of circumferences.
If we make a circle and fill all of its interior, it will become a circle. This, in turn, is formed by a circle and by the infinite points that fill its interior. For example, a nice, juicy pizza might represent a circle. The pizza is shaped like a circle, but deliciously filled! A wall clock can also be a circle, as long as its extremities feature a circumference, as its entire center will certainly be filled. Note that the circle it is a flat figure like the circumference.
A pizza represents a circle because its end is a circle and its interior is filled.
What if we now have a circular shape, but instead of being flat, it's three-dimensional? In that case, then we have a sphere. One ball has the possibility of being filled with air, water or any other substance and still characterized by being a shape that can rotate or roll when placed on a surface such as a table or in floor. And if, by chance, we cut it, dividing it into two parts, the place where we cut it will have the shape of a circle.
The balls in a ball pool represent numerous colored spheres.
And now, can you tell what the hula hoop, plate and ball are that appear in the first image of the text? O hula hoop features a circumference, as it does not have a fill; O plate symbolizes a circle, because its entire interior is filled; and the ball represents a sphere, because, in addition to being three-dimensional, it is a circular shape.
