Library of GSP Scripts

These are Geometer Sketch Pad scripts for creating the described shapes and phenomena


Centroid

The point of intersection of a triangle's medians (the segments connecting each vertex to the midpoint of the opposite side). The centroid is the triangle's "center of gravity".


Orthocenter

The point of intersection of the lines containing the altitudes of a triangle.


Circumcenter

The point of intersection of the sides' perpindicular bisectors

 

 

 


Circumcircle The circle created using the circumcenter as its center and a

vertex of the triangle as an outside point; the circumcircle contains the entire triangle.


Incenter and Incircle

The incenter is the point of intersection of the triangle's angle bisectors - it is a point equidistant from all sides of the triangle. The incircle is a circle created with the incenter as its center and with the triangle as its size. Regardless of the triangle's shape or size, the incircle will stay inside the triangle.


 

Triangle Centers (H,G,C,I): The circumcenter, orthocenter, centroid and incenter of a triangle.


 

Triangle Centers with Euler Line The Euler Line connects the circumcenter, orthocenter and centroid.

 

 

 

 

 

 


Medial Triangle

A triangle created by creating segments connecting the midpoints of the sides of the triangle.

 


Orthocenter, of a MedialTriangle

 

 

 


Orthic Triangle: A triangle created by the segments connecting the base points of the 3 altitudes of a triangle.


Pedal TriangleA pedal triangle is created by taking any point on the plane, P, and creating segments between the feet of the perpindicular lines created between the point and the lines extending from the sides of the original triangle.


Center of Nine Point Circle: A nine point circle created to include the three mid-points of the sides of the triangle, the three feet of the altitudes of the triangle, and the three mid-points of the segments created between the vertices and the orthocenter. The center of the circle is then created at the intersection of perpindicular lines created from the midpoints of the segments between any two neighboring points included on the circle.


Nine Point Circle: Created using the center found above and any of the nine points included on the circle.

 

 

 

 

 


Trisecting a Line Segment

This script uses radial measures and intersecting lines to trisect a line segment.


Equilateral Triangle, Given a Side


 

Square, Given a Side

This script uses radial measures and perpindicular and parallel lines to create a square from a given side of the square.

 

 

 

 

 

 


 

Divide a Segment into Two Parts that Form a Golden Ratio

 

 


Pentagon, Given a Side: Uses radial measures to create a pentagon from a given side.


Hexagon, Given a Side: Uses radial measures, parallel and perpindicular lines to create a hexagon from a given side.


 

Octagon, Given a Side: Uses radial measures, parallel and perpindicular lines to create an octagon from a given side.



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