That would be the vascular system.
Lines of latitude stay where they are and do not run anywhere. Every one of them forms a complete circle around the world.
The half circle of 180 degrees of arc connecting the Earth's poles is known as a great circle. This is the largest circle that can be drawn on a sphere and it divides the sphere into two equal hemispheres.
A circle inside another circle is called a concentric circle. This means that the circles share the same center point, with one circle contained entirely within the other.
The pituitary gland is a small endocrine gland in the brain. It sits a bony structure on the cranial floor called the Sella Turcica, which translates to Turkish saddle, named for the shape of the structure. When looking at the blood vessels of the brain the pituitary is very easy to locate. It sits in the middle of the circle of Willis, a ring a blood vessels at the heart of the 'lobster-like' network.
A solid in the shape of a circle is called a cylinder.
A cone.
The line connecting the points is called a chord; the part of the perimeter of the circle enclosed is called an arc; the area between an arc and the chord is called a circular segment.
A chord of a circle that contains the center of the circle is called a diameter. The diameter is the longest chord in the circle and divides it into two equal halves. It passes through the center, connecting two points on the circumference.
The radius of a circle is one half of the circle's diameter, any line going from the center of the circle to the circle itself. A line connecting other points on a circle (or on any curve) is called a chord.
The circle and the square are the two parents.
That's a full moon.
Semi-circle
When the moon is a complete circle, it is called a full moon. This occurs when the Earth is between the sun and the moon, with the side of the moon facing Earth fully illuminated by the sun.
a chord of the circle
No. That's a radius.
The largest chord in a circle is called the diameter. It spans the widest part of the circle, connecting two points on the circumference and passing through the center. The diameter is always twice the length of the radius of the circle.
.... center