TRIANGLE MIDSEGMENT INVESTIGATIONS The midsegment of a triangle is a line segment that connects the midpoint of one side of a to the midpoint of another side. Triangles have 3 midsegments. The midsegments have a number of interesting properties which we will explore in this investigation.
Step 1: Using the triangle underneath "Midsegment Length Investigation", Compare the measurements of the midsegments (red) with the corresponding bases (brown). Drag a vertex of the triangle and observe the lengths of the corresponding bases and midsegments How do the measurements of the midsegment and the base compare?
Step 2: Write a TRIANGLE MIDSEGMENT LENGTH CONJECTURE on your paper.
Step 3: Using the triangle underneath "Midsegment Angle Investigation", Compare the measurements of the angles formed by the midsegments (red) and the side (brown), and the two sides. What types of angles are these? What is the measurement of these angles? Are they congruent? Drag a vertex of the triangle and observe the measures of these angles If these angles are always congruent, what can we say about the midsegment and the base?
Step 4: Write a TRIANGLE MIDSEGMENT PARALLEL CONJECTURE on your paper
Step 1: Using the triangle underneath "Midsegment Length Investigation", Compare the measurements of the midsegments (red) with the corresponding bases (brown). Drag a vertex of the triangle and observe the lengths of the corresponding bases and midsegments How do the measurements of the midsegment and the base compare?
Step 2: Write a TRIANGLE MIDSEGMENT LENGTH CONJECTURE on your paper.
Step 3: Using the triangle underneath "Midsegment Angle Investigation", Compare the measurements of the angles formed by the midsegments (red) and the side (brown), and the two sides. What types of angles are these? What is the measurement of these angles? Are they congruent? Drag a vertex of the triangle and observe the measures of these angles If these angles are always congruent, what can we say about the midsegment and the base?
Step 4: Write a TRIANGLE MIDSEGMENT PARALLEL CONJECTURE on your paper
The centroid of a triangle is it's center of balance or center of gravity. It is the point of concurrency of the medians of a triangle. Medians are found by connecting the midpoint of each side to the opposite vertex.
Use the applet below to explore the following questions:
What relationship do you notice between the segments AG and AE?
What relationship do you notice between segments CG and CD?
What relationship do you notice between segments GE and AE?
Use the distance tool to determine what kind of segments create a centroid. Does the centroid of a triangle ever lie outside a triangle?
Use the applet below to explore the following questions:
What relationship do you notice between the segments AG and AE?
What relationship do you notice between segments CG and CD?
What relationship do you notice between segments GE and AE?
Use the distance tool to determine what kind of segments create a centroid. Does the centroid of a triangle ever lie outside a triangle?
The last concurrency we want to look at is the meeting of the altitudes: The orthocenter.
You can explore more about the orthocenter here.