For Class on Wednesday, March 18, 2009

Please work on the review to chapter 4, problem 1-37 on pages 249 to 252. We will be working on these problems all week, with an assessment on Friday. As the week goes by I want to post your answers and make videos for many of these problems. Work together, stay focused. Three half-days this week, but we can do a lot of work during half-days if we try!!! Work with each other, have fun!

1. Because of the SSS triangle, once the distances of the three sides are fixed the angles cannot change. Using triangles to build something makes everything very rigid. But if you use squares the angles can easily change, the square will become a rhombus.








2. The triangle sum conjecture states that the sum of the measures of the angles in
every triangle is 180 degrees. It is the most important because it applies to all triangles, and many other conjectures rely upon it.

3. In an isosceles triangle the angle bisector of the vertex angle is also a median line and an altitude. Remember that a median line goes from the midpoint of one side of a triangle to the vertex opposite, an angle bisector splits an angle in half, and an altitude is perpendicular to the side opposite a vertex going through the vertex. See video here.

4. This is the question: What does the statement "the shortest distance between two points is the straight line between them" have to do with the Triangle Inequality conjecture? (Remember this conjecture states the sum of the length of any two sides of a triangle must be more than then third length.)

5. The four congruence shortcuts are SSS, SAS, ASA, and SAA. Can you explain why AAA is not a congruence shortcut?

6. Can you explain why SSA is not a congruence short cut? Hint: make two triangles on geogebra that have two sides the same and one angle (but not the included angle, which means the angle inbetween the two sides) but yet are different.