Create parallel lines from congruent angles
Unit 3
To open Geogebra.
Click icon on desktop, if not there Go to www.Geogebra.org
Click Download
Choose Webstart
Begin your lesson:
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Open a new document in Geogebra
Create two points A and B anywhere on your document.
Draw a line through the two points
Create a third point C not on your line.
Construct line AC.
Measure angle BAC, an acute angle.
Create an angle with the same measure as angle BAC by selecting Angle with Given Size and
clicking AC then input the measure of angle BAC and clockwise.
8. Complete the construction of the parallel lines by connecting two points.
9. Add a text box (ABC) and type in the theorem that supports your construction.
To Print your document
Go to File, Print Preview. In Print Preview choose the View All (make sure you can see your triangle).
Title the document Parallel lines created by congruent angles. Type your name as the author. Then hit
Print.
10. Open a new document and construct parallel lines using another angle pair. Be sure to add a
text box and type the theorem that supports your claim.
11. Go to File, Print Preview. In Print Preview choose the View All (make sure you can see your
triangle). Title the document Second pair of parallel lines. Type your name as the author. Then
hit Print.