They're called protractors.
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The metal tool you are referring to is called a compass. A compass consists of two arms, one holding a pencil and the other with a pointed end that acts as the center of the circle. By adjusting the distance between the two arms, you can create circles of various sizes with precision and accuracy.
The default method for drawing a circle is to specify a center point and radius.You can draw circles using any of the following methods:Center-RadiusCenter-DiameterTwo pointsThree pointsRadius-Tangent-TangentConvert Arc to CircleTo draw a circle by specifying its center and radiusDo one of the following:Choose Draw> Circle>center, radiusOn the Draw 2D toolbar, click the Circle Center-Radius tool.Type circle and then press Enter.Specify the center point.Specify the radius of the circle.
first you draw a circle, divide it into 4
Draw a circle, then move the point of your compass before you draw another one.
As far as an UNAIDED human, no it is not possible. By unaided - nothing other than their writing utensil, hand and the surface being drawn on with no guide, tools, marks or the like.