Today's goal: copy a triangle by copying three segments; construct 90 degree angle, 45, and 135; construct altitudes in triangles; construct parallel lines; construct angle bisectors in triangles; discover that points on the angle bisector are equidistant from the sides of the angle, allowing us to construct a circle that touches both sides of the angle.
We wrote up the definition of altitude and copied sketches from p 154. We wrote up C-7 from p 153. The fill-in-the-blank is "perpendicular". The sketch is above the conjecture. Label: PM is the shortest distance. We also added problems 7 and 9 from p 159 to HW #13. A grade was taken on HW #13 for 4 pts.
Quiz topics were passed out, as well as homework #14 worksheet. Add to your worksheet: p 159:10, p 162: 1 or 2, p 155:10 in some classes. Topics and worksheet are downloadable below.
We did an investigation together to discover C-8: Every point on the angle bisector of an angle is equidistant from the sides of the angle. This was done on patty paper. Can be glued into your geometric truth.
We tried a construction of parallel lines based on looking at several. If you have trouble with this on your homework, google: mathopenref constructions