Centers of a Triangle

New vocabulary words:

1. incenter- point of concurrency of 3 angle bisectors of a triangle
2. orthocenter - point of concurrency of 3 altitudes of a triangle
3. circumcenter - pt. of concurrency of 3 perpendicular bisectors of a triangle
4. centroid - point of concurrency of 3 medians of a triangle

I know I said I wouldn't do this, but I can't stand to watch some of you struggle. The following website may help those of you who are having a tough time with constructions. The sound may be choppy the first time.

Allow it to play all the way through and

then listen to it again.

It'll come out clear the second time you listen to it.

http://regentsprep.org/Regents/math/math-topic.cfm?TopicCode=construc

Your assignment this weekend is:

1. Construct the incenter of a large acute triangle.
2. Construct the incenter of a large obtuse triangle
3. Construct the inscribed circle of # 1 and # 2.
4. Construct the orthocenter of a large acute triangle.
5. Construct the orthocenter of a large obtuse triangle.
6. Construct the circumcenter of a large acute triangle.
7. Construct the circumcenter of a large obtuse triangle.
8. Construct the circumscribed circle of # 6 and #7.
9. Construct the centroid of a large acute triangle.
10. Construct the centroid of a large obtuse triangle.

Any questions? Post them here. Do you know constructions well? Post your steps here. Just a suggestion: form a study group at Barnes and Noble this weekend. Have a cafe mocha while performing constructions. Wahoooooo! Fun! Fun!