**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.
**Standard(s): **

[MA2015] GEO (9-12) 26: Construct the inscribed and circumscribed circles of a triangle, and prove properties of angles for a quadrilateral inscribed in a circle. [G-C3]

**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.

**Title:** Triangle Classification

**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.
**Standard(s): **

[MA2015] GEO (9-12) 26: Construct the inscribed and circumscribed circles of a triangle, and prove properties of angles for a quadrilateral inscribed in a circle. [G-C3]

**Subject:**Mathematics

**Title:**Triangle Classification

**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

**Title:** IGD: Euler Line

**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.
**Standard(s): **

[MA2015] MI1 (9-12) 11: Describe the development of mathematical tools and their applications. (Alabama)

**Subject:**Mathematics

**Title:**IGD: Euler Line

**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

**Title:** IGD: Median

**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.
**Standard(s): **

[MA2015] GEO (9-12) 26: Construct the inscribed and circumscribed circles of a triangle, and prove properties of angles for a quadrilateral inscribed in a circle. [G-C3]

**Subject:**Mathematics

**Title:**IGD: Median

**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

**Title:** IGD: Simson Line

**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.
**Standard(s): **

[MA2015] MI1 (9-12) 11: Describe the development of mathematical tools and their applications. (Alabama)

**Subject:**Mathematics

**Title:**IGD: Simson Line

**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