Constructing triangles given the side lengths

Move AD, BE and CF to determine the side length of the triangle.

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1.) Use the segment to construct the following triangles:
 a.) equilateral
 b.) scalene
 c.) isosceles
 d.) right

2.) Construct a triangle with side lengths 2, 2, and 4. What do you observe?
3.) Explain why your observations are such.

Download GGB file

The ASA Triangle Congruence

In the figure below, the angles of triangles 1 and 2 which have the same color are congruent.  The side between the two angles of the two triangles are also congruent.

1. Move the vertices of triangle ABC. What do you observe?
2. Use the tools provided to investigate the triangle. List your observations. 
3. Make a conjecture of what you have observed. 

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The ASA triangle congruence postulate (actually, it's a theorem), states that if the two corresponding angles of two triangles are congruent, and the corresponding included sides are congruent, then the two triangles are congruent.

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This article is sponsored by Euroffice for office whiteboards.

Conjectures and Proof in GeoGebra

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AA Similiarty

This applet is for teachers. Feel free to supply the questions/explanations.




















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