On this page I am compiling a library of scripts that may be useful, especially when iterating constructions with The Geometer's Sketchpad, GSP. Try them out!

**Orthocenter****of a triangle**. To use this script, start with three points on a GSP sketch. Make sure the three points are selected before you press "play" on the script.

**Centroid****of a triangle**. Start with three points on a GSP sketch.

**Circumcenter****of a triangle**. Also known as the construction for a**circle****that passes through a given three points**. The circle is called the**circumcircle**of the triangle. Start with three points on a GSP sketch.

**Incenter****of a triangle**. Also known as the construction for a**circle that is tangent to three sides of a triangle**. The circle is called the**incircle**of the triangle. Start with three points on a GSP sketch.

**Excircles****of a triangle**. Start with three points on a GSP sketch.

**Nine-Point Circle****for a triangle**. This construction will produce the diagram I used in Write Up #4.

**Euler Line****of a triangle**. Start with three points on a GSP sketch.

**Pedal Triangle**. Start with three vertices of a triangle and any point in the plane of the triangle.

**Equilateral Triangle**. Start with two points on a GSP sketch.

**Square**. Start with two points on a GSP sketch.

**Pentagon, given a radius**;**Pentagon, given a side**. Start with two points on a GSP sketch in each case.

**Hexagon**. Start with two points on a GSP sketch.

**Trisection of a segment**. Start with two points on a GSP sketch.

**Division of a segment****into the Golden Ratio**. Start with two points on a GSP sketch.

**Tangent Circle 1**--**construction of a circle tangent to two given circles such that it contains neither**. Start with four points on a GSP sketch.

**Tangent Circle 2**--**construction of a circle tangent to two given circles such that it contains one of the circles**. Start with four points on a GSP sketch.