1. Lesson 3.7 & 3.8: 1.Homework Collection 2.Constructions

2. Warm Up: Make sure you have the following items at your desk: 1.Paper 2.Pencil 3.Compass 4.Straightedge Complete the Warm Up handout and add it to your notes.

3. Point of Concurrency: A point of concurrency is a point of intersection for 3 or more lines. Concurrent lines Not concurrent lines

4. Activity #1: Angle Bisector Concurrency – do you think the angle bisectors of a triangle will be concurrent? Using the Handout (#1), a compass, and a straightedge, construct the angle bisectors of triangle ABC.

5. Summary: Add this to your Learning Targets Packet. The three angle bisectors of a triangle ______________________________. They meet at a point called the ______________.

6. Activity #2: Perpendicular Bisector Concurrency – do you think the 3 perpendicular bisectors of a triangle will be concurrent? Using the Handout (#2), a compass, and a straightedge, construct the perpendicular bisectors of each side of each triangle.

7. Summary: Add this to your Learning Targets Packet. The three perpendicular bisectors of a triangle _____________________________. They meet at a point called the _______________.

8. Activity #3: Altitude Concurrency – do you think the 3 altitudes of a triangle will be concurrent? Using the Handout (#3), a compass, and a straightedge, construct the altitudes of each side of each triangle. (Construct a perpendicular from a point off the line.)

9. Summary: Add this to your Learning Targets Packet. The three altitudes (or the lines containing the altitudes) of a triangle ___________________. They meet at a point called the ______________________.

10. Activity #4: Median Concurrency – do you think the 3 medians of a triangle will be concurrent? Using the Handout (#4), a compass, and a straightedge, construct the medians of each side of each triangle. (Find the midpoint of each side by finding the perpendicular bisector and then connect the midpoint to the opposite angle.)

11. Summary: Add this to your Learning Targets Packet. The three medians of a triangle ___________________________. They meet at a point called the ______________________. Look at p. 186 – we will do this together.

12. Thoughts: For what kind of triangle will the incenter, circumcenter, and orthocenter be at the same point? What about the cen What about the centroid??

13. Homework: P. 172-173: 8, 12 P. 193-195: 1-18 all