compass

rule

Method/step 1:

Prepare a compass, pack the refill, pack the compass and put it in a better position than the pen.

Method/Step 2:

Determine where the center of the circle is

Method/Step 3:

Draw a straight line in one direction of the center of the circle. Confirm the radius of the circle to be drawn, prepare a ruler and draw a straight line with the pen end of the compass.

Method/Step 4:

Place the long side and needle tip of the compass in the center of the circle.

Method/Step 5:

Then put the pointed end at the center of the circle, and the end with the pen is full and open at the end of the radius just drawn.

Method/Step 6:

The compass on the long side does not move, so we touch the top of the compass with our head and turn it gently, thus drawing a circle.

A circle is a seemingly simple shape, but in fact it is very wonderful. The ancients first got the concept of circle from the sun and the moon on the fifteenth day of the lunar calendar. /kloc-Neanderthals 0/8000 years ago used to drill holes in animal teeth, gravel and stone beads, some of which were round. In the pottery age, many pottery were round. Round pottery is made by putting clay on a turntable. When people start spinning, they make round stone spindles or ceramic spindles. The ancients also found it easier to roll when carrying logs. Later, when they were carrying heavy objects, they put some logs under big trees and stones and rolled them around, which was of course much more labor-saving than carrying them.

About 6000 years ago, Mesopotamia made the world's first wheel-a round board. About 4000 years ago, people fixed round boards under wooden frames, which was the original car.

You can make a circle, but you don't necessarily know its nature. The ancient Egyptians believed that the circle was a sacred figure given by God. It was not until more than two thousand years ago that China's Mozi (about 468- 376 BC) gave the definition of a circle: a circle, a circle of equal length. It means that a circle has a center and the length from the center to the circumference is equal. This definition is 100 years earlier than that of the Greek mathematician Euclid (about 330 BC-275 BC).