This applet demonstrates the principles behind side-angle-side congruency (SAS).
Instructions for creating the applet:
[b]SAS[/b]
1. Hide the axes.
2. Using the input bar, enter “AC = 1,” “AD=1,” and “CAD=45.”
3. Click the radio next to these variables in the algebra pane to show their sliders.
4. Adjust the preferences for these sliders. Let 0<AC<5, 0<AD<1 (both with increments of 0.01) and 0<CAD<360 (increments of 0.1).
5. Create a point A.
6. Create a line through A passing through a second point, B.
7. Using the Circle with Center and Radius tool, create a circle with center at A and radius AD.
8. Create a point D where this circle intersects the line AB.
9. Hide the line and circle (or make them dashed) and create a solid segment from A to D. Leave B visible.
10. Using the Angle with Given Size tool, create an angle of size CAD degrees counterclockwise from AD. Be sure to leave the degree symbol when defining the angle size.
11. Create a line passing through AD’.
12. Create a circle with center at A and radius AC.
13. Hide or fade the circle and line AD’ and the point D’.
14. Create a solid segment from A to C.
15. Create a dashed segment from C to D (since we haven’t directly defined this segment).
16. Hide the algebra view.
17. Format the sliders so the colors match the colors of the line segments of the triangle.
