Bisecting line segments and bisecting angles must be mastered in geometry learning. Before, they were drawn with rulers and rulers. Now, with the help of the geometric sketchpad, you can quickly achieve equal divisions. For example, to construct the third points of an equilateral triangle, Let's learn the specific production skills together.
Geometric Sketchpad software is special for the beginning of school, the software acquisition address: http://wm.makeding.com/iclk/?zoneid=17783
Method 1 Use the zoom command
You can mark one endpoint of the line segment as the center, select the other endpoint, execute the "Transform" - "Scale" command, the scaling ratio is 1:3, and then scale it again, the ratio is 2:3.
Step 1 Open the Geometric Sketchpad math courseware making tool , draw an equilateral triangle ABC, double-click point B to mark it as the zoom center, select point C, execute the "Transform" - "Scale" command, and enter the scale as 1 in the pop-up dialog box. : 3, click "OK" to get the third point D.
Example of executing the zoom command to get the trisection point D of the edge BC
Step 2 Then select point C, execute the "Transform" - "Scale" command, enter the scaling ratio as 2:3 in the pop-up dialog box, and click "OK" to get the third point E.
Example of executing the zoom command to get the trisection point E of the edge BC
Reminder: According to the above steps, you can find the trisection point of each side for research, so I won't introduce it here.
method two-point method
Use the value of the point to draw a point on the edge of the equilateral triangle, right-click on the edge, execute the "Draw Point on Line Segment" command, and enter "1/3" and "2/3" respectively.
Step 1 Draw an equilateral triangle ABC, use the "point tool" to draw a point D on the side BC, and execute the "measure" - "point value" command to get the value of the point on the side BC.
Example of value of point D on measure edge BC
Step 2 Select the edge BC, right-click the mouse, select the "Draw point on the line segment" command, enter "1/3" in the pop-up dialog box, click to draw, and get the third point E.
Example of Plotting Trisection Points Using Point Values
Step 3 Then execute the command again and enter "2/3", click Draw, and then click Finish to get the trisecting point F of side BC, as shown in the following figure.
Example of drawing a trisection point F using the value of the point
Reminder: According to the above method, the trisection points of the remaining two sides can be constructed, which will not be described in detail here. In addition, you can also use the geometric sketchpad to bisect line segments. If you have any questions, please refer to: How to use the geometric sketchpad to divide line segments .
After reading the above tutorials, I have learned two methods of constructing trisection points in the geometric sketchpad. The first method is relatively simple and can be completed by using the zoom command; the second method uses the "point value" to construct the bisection point with the help of the value of the point. It is difficult to understand, but it can be mastered with more practice.
The above tutorials are referenced from: http://www.jihehuaban.com.cn/xinshourumen/sandeng-fen.html