ALEX Lesson Plans
Subject: Mathematics (9  12) Title: Investigation of Special Segments of Triangles
Description: This lesson will enable students to investigate three special segments of triangles in a very concrete way. The students will fold paper triangles to create the segments. This lesson would be a great way for students to explore the properties of the segments and their intersections.
Thinkfinity Lesson Plans
Subject: Mathematics Title: IGD: Euler Line
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Description: This student interactive, from Illuminations, helps students understand and investigate Euler lines. Students read a definition and then construct the Euler line of a triangle using the interactive tool. They learn that the Euler line involves three points associated with triangles: the circumcenter, orthocenter, and centroid. Thinkfinity Partner: Illuminations Grade Span: 9,10,11,12
Subject: Mathematics Title: IGD: Median
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Description: This student interactive, from Illuminations, helps students understand and investigate the median of a triangle. Students read a definition and then use the interactive tool to manipulate and explore the properties of triangle medians by changing the shape of a triangle. Thinkfinity Partner: Illuminations Grade Span: 9,10,11,12
Subject: Mathematics Title: Triangle Classification
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Description: This transparency, from an Illuminations lesson, asks students to identify all points that create right, obtuse, isosceles, acute, scalene and equilateral triangles when given an AB segment. Thinkfinity Partner: Illuminations Grade Span: 9,10,11,12
Subject: Mathematics Title: IGD: Simson Line
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Description: This student interactive, from Illuminations, helps students understand and investigate a triangle s Simson line, which is the line passing through the feet of the perpendiculars dropped from P to the three sides of a triangle. Students construct the Simson line for a given triangle using the interactive applet. Thinkfinity Partner: Illuminations Grade Span: 9,10,11,12

