A triangle is completely determined if we know 2 "sides" and the size of the angle between them. There are 2 "sides" and an angle on the drawing pad.
Let's assemble the triangle!
First - click on Goal button to see our goal (hang-on a bit, sometimes it takes it a few seconds)
and then click on Reset to start.
Start: Assemble the triangle with the given sides and angle.
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Click and drag point A onto the vertex of the angle. Then click and drag point B so that the side AB lies on the lower ray of the angle.
- Click and drag point A1 onto the vertex of the angle. Then click and drag point C so that the side AC lies on the upper ray of the angle.
Now, notice that the length of the side BC is fixed. There are no extra possibilities
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Select the 'Segment between two points' tool and click on B and C to complete the triangle.
- Now click again on the Reset to start over.
- Select the 'Move' tool. Click and drag the sliders to whatever values you want and follow the instructions from Start again.
End: Notice that once you make the triangle you cannot use the angle slider. Why is this?
In the next exercise, you will construct a triangle using SAS - not just assemble. Then everything will work properly. Click on the Next button to go to this exerise.
Authors: LFS, Created with GeoGebra