bell ringer 3-28-18 1. What is an angle bisector? How many are in a triangle? 2. What is a perpendicular bisector? How many are in a triangle? 3. What is a median? How many are in a triangle?

Points of concurrency Wednesday, march 28, 2018

Centroid The centroid is the point of intersection of the medians of a triangle. (The centroid is always inside the triangle.) From the centroid to the side of the triangle is 1 3 of the median. From the centroid to the angle is 2 3 of the median. Find the centroid of your right triangle.

examples

Circumcenter The circumcenter is the intersection of the perpendicular bisectors of the sides of triangles. The circumcenter is the center of the circle that can be circumscribed about the triangle. The circumcenter is equidistant from the angles of the triangle. Find the circumcenter of your acute triangle.

examples

incenter The incenter is the point of concurrency of the angle bisectors of a triangle. (The incenter is always inside the triangle.) The incenter is the center of the circle that can be inscribed in the triangle. The incenter is equidistant from the sides of the triangle. Find the incenter of your obtuse triangle.

examples

Strange things happen… Find all three points of concurrency of your equilateral triangle. What do you notice?

exit ticket 1. What makes a centroid? 2. What makes a circumcenter? 3. What makes an incenter? Homework  Points of Concurrency