In this activity, students investigate the midsegments of a triangle as in the previous activity. They continue to explore these segments and extend their understanding of the relationships that exist between the slopes of lines containing the segments. NCTM Geometry Standard covered: Analyze characteristics and properties of 2- and 3-dimensional geometric shapes and develop mathematical arguments about geometric relationships.

Distribute the pages to your class.

Follow the Activity procedures:

• Draw a triangle
• Find the midpoints of two sides
• Draw a segment to join the midpoints
• Explore the relationships between the segment and the third side of the triangle - their lengths and the slopes of the lines containing the segments
• The segment joining the midpoints of two sides of a triangle is parallel to the third side and has measure equal to one-half the measure of the third side
• Test these conjectures using different sides of the triangle

Review student results: