Wingeom: Incenter & Incircle
The Incenter of a triangle is formed by the three angle bisectors of a triangle, which meet in a common point. The Incenter is the center of the Incircle, which is tangent to the three edges of the triangle. The Incenter always lies in the triangle.
Getting Started
Double click on the Wingeom icon. Inflate the frame (if not already inflated), by clicking on the 2nd of these three icons: - [] X. Select Window/2-dim. Inflate the new frame.
Construct Triangle ABC
With the mouse in the Btns / Segment mode, use the right mouse button to place point A, B, and C on the screen, see the diagram above. Connect A to B to C.
Constructing the Angle Bisectors and Their Intersection
Select Line / Angles / Bisect old. Angle labels must be typed in a clockwise fashion, i.e. <BAC, <ACB, < CBA, ok. Select Point / Intersection / Line-line. Type in BF, CE, mark, close. G, the intersection of the medians, is the Incenter of the triangle.
Adjust the Figure
Use Btns / Drag Vertices or Btns / Text to adjust points and labels.
Drawing the Radius of the Incircle
Select Line / Perpendiculars / Altitudes. Type BC and G, draw, close. GH is the radius of the incircle.
Drawing the Incircle
Select Circle / Radius-center. Centered at G; (●) circle through H, draw, close.
Writing Text on the Screen
Put the mouse in the Btns / Text mode. Right click on the screen where you want the text to appear. Type Incenter & Incircle on the screen, repeat for your name, teacher’s name, period, and date. Move text as needed.
Printing the Document
Before you print your document, it is very important to check that you have the proper format. Do File / Format, change the upper number to 25 / ok. The horizontal and vertical offsets should be 2.54. We want to print the document in landscape mode. The following set of commands will work on some computers; others might have a different set of commands. Do File / Print / Properties / Basics (Layout) / Landscape, ok. After formatting, print the document in the usual way.