Chapter 3 Part 3: Constructions ~ Incenter, Circumcenter, Orthocenter , and Centroid (Triangles)
The point of concurrency of the three angle bisectors of a triangle is the incenter. It is the center of the circle that can be inscribed in the triangle, making the incenter equidistant from the three sides of the triangle. To construct the incenter, first construct the three angle bisectors; the point where they all intersect is the incenter. The incenter is always located within the triangle.
The point of concurrency of the three perpendicular bisectors of a triangle is the circumcenter. It is the center of the circle circumscribed about the triangle, making the circumcenter equidistant from the three vertices of the triangle. The circumcenter is not always within the triangle. In a coordinate plane, to find the circumcenter we first find the equation of two perpendicular bisectors of the sides and solve the system of equations.
The orthocenter is the point of concurrency of the altitudes in a triangle. A point of concurrency is the intersection of 3 or more lines, rays, segments or planes. The orthocenter is just one point of concurrency in a triangle. The others are theincenter, the circumcenter and the centroid.
The centroid is the point of concurrency of the three medians in a triangle. It is the center of mass (center of gravity) and therefore is always located within the triangle. The centroid divides each median into a piece one-third the length of the median and two-thirds the length. To find the centroid, we find the midpoint of two sides in the coordinate plane and use the corresponding vertices to get equations.
The point of concurrency of the three perpendicular bisectors of a triangle is the circumcenter. It is the center of the circle circumscribed about the triangle, making the circumcenter equidistant from the three vertices of the triangle. The circumcenter is not always within the triangle. In a coordinate plane, to find the circumcenter we first find the equation of two perpendicular bisectors of the sides and solve the system of equations.
The orthocenter is the point of concurrency of the altitudes in a triangle. A point of concurrency is the intersection of 3 or more lines, rays, segments or planes. The orthocenter is just one point of concurrency in a triangle. The others are theincenter, the circumcenter and the centroid.
The centroid is the point of concurrency of the three medians in a triangle. It is the center of mass (center of gravity) and therefore is always located within the triangle. The centroid divides each median into a piece one-third the length of the median and two-thirds the length. To find the centroid, we find the midpoint of two sides in the coordinate plane and use the corresponding vertices to get equations.
Notes and Powerpoints
chapter_3-part_3-geometers_sketchpad.pdf | |
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gsp_chapter_3-part_3.gsp | |
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File Type: | gsp |
Homework/Classwork
chapter_3_constructions_assignment_3.pdf | |
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