We draw eight equal circles with a protractor and a ruler:
Method 1:
Make two diameters by the center of the circle, so that the two diameters are perpendicular to each other (with a protractor), so as to know that the circle has been quartered;
Measure an angle of 45 degrees through the center of the circle, and then make a straight line to make it pass through the center of the circle;
Make a diameter perpendicular to the straight line in step 2;
To sum up, the four straight lines of a ***4 * are actually four diameters and are divided into eight equal circles;
Method 2:
Draw any diameter on the circle;
Make an angular bisector (imagine the diameter as a right angle), (divide the right angle into two right angles) and then make an angular bisector;
Extending the angular bisector in the opposite direction on the circle to obtain the bisector;
Method 3:
1. Make the circumscribed circle o of the square ABCD.
2. Make a vertical line to any side (set as AB) passing through the center of the circle and extend it. The extension line intersects the arc at point E ...?
3. Then the compass measures the AE length, and then draws an arc with A and C as the center to get the intersection points with circle O, which are E, F, G and H respectively. ?
4. Connect EAFBGCHD, which is a regular octagon.
: 1. Divide by a certain number, that is, enter the shortcut key DIV in the command bar and press enter, select the space of the circular object, and then enter how many segments to divide equally. At this time, the effect of equal division cannot be displayed, because the shape of the point is still a solid point by default. Therefore, the effect can only be displayed by setting points. (Enter the space "DDPTYPE" in the command bar, and then select the style of the point to display it)
2. MeasureMEnt: Enter the shortcut key "me" in the command bar, select the space of the circle object, and then enter the line segment length value. As for the display effect setting, the same as above.
References:
Baidu encyclopedia-equal circle