Angle-Side-Angle Postulate Demonstration.
Using GeoGebra, we can demonstrate the Angle-Side-Angle Postulate. Since this is a postulate and cannot be proven, we rely on an example to demonstrate. If we start by creating segment AB of fixed length (7) with angles alpha and beta on either side, we may finish the construction by completing the triangle. Now if we make a second segment EF of fixed length (7) outside the triangle ABC, we may attach angles on either endpoint of the segment similar to the first triangle. Completing the triangle and measuring the remaining segments and angles show that the triangles have 6 corresponding congruent parts, implying congruent figures.