Given two points above the
x-axis, there is a unique semicircle through those points with its
diameter on the x-axis. We'll create a tool that constructs that
semicircle. To the right we place points A and B, then use the Perpendicular Bisector tool ![]() ![]() Next, construct a circle ![]() |
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We can use the Intersect Tool ![]() ![]() So, we start with points A and B, and we end with the semicircle semi. Now we'll create a tool that does this immediately. |
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From the menu select Tools > Create New Tool... In the Output Objects tab, select the semicicle semi. In the Input Objects tab, select points A and B (use shift-click or ctrl-click to select both). |
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In the Name & Icon tab, type a name
for your new tool; I used SemicircleOnXAxis
. You can't use spaces, and you can also use this name as a
command in the Input Bar. If you have a picture you'd like to use, you can select it by clicking the Icon... button. Click finish! |
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Now you can use the new
tool. Create two points, click on the tool, then select those two
points - instant semicircle! Now let's save the tool so we can use it in other constructions. |
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In the menu select Tools > Manage Tools... Select SemicircleOnXAxis then click Save As... You'll be asked to save a file with .ggt extension. Save your file as SemicircleOnXAxis.ggt . After creating a new user defined tool you can save your settings using menu Options > Save Settings. From now on, your customized tool will be part of the GeoGebra Toolbar. Or, after saving your custom tool on your computer (as a ggt file), you can import it into a new GeoGebra window by selecting File > Open and opening the file of your custom tool. Opening a GeoGebra tool file (ggt) in GeoGebra doesn’t affect your current construction. It only makes this tool part of the current GeoGebra Toolbar. |
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