Points of Concurrency

Centroid
1. Choose the "Polygon" tool and draw a large triangle.[br]2. Choose the "Point" tool and select Midpoint. Use this tool to locate and mark the midpoint of each side of the triangle.[br]3. Choose the "Line" tool and select Segment. Use this to draw a segment from each midpoint to the vertex across from it.[br]4. Use the "Point" tool to mark the intersection of all these segments.[br]5. Choose the "Measure" tool (fourth from the right) and select Distance or Length. Measure the length of all six segments that are inside your triangle. [Each segment you drew earlier is now broken into two segments.][br]6. What do you notice about the lengths of these segments? Does your observation hold true if you move the vertices of the triangle? Try several different triangles to find out![br]7. On your paper, sketch a picture of your triangle with the inside segments drawn. Fill in the blanks provided.
Centroid
Incenter
1. Draw a large triangle.[br]2. Choose the "Construct" tool (fourth from the left) and select Angle Bisector.[br]3. Use the tool to create an angle bisector at each vertex of the triangle. [To do this, select three points in a row. The middle selection is where your line will be drawn.][br]4. Use the "Point" tool to mark the intersection of your three lines.[br]5. Choose the "Circle" tool and select Circle with Center through Point. Use it to draw a circle whose center is your Incenter and which touches at least one [i]side[/i] of your triangle.[br]6. What do you notice about this circle? What does that mean about the distance from each side to the incenter?[br]7. On your paper, sketch a picture and fill in the blanks.
Incenter
Circumcenter
1. Draw a large triangle.[br]2. Choose the "Construct" tool and select Perpendicular Bisector. [br]3. Use the tool to create a perpendicular bisector on each side of the triangle. [To do this, select the two points at the end of a side. Repeat for each side.][br]4.Use the "Point" tool to mark the intersection of your three lines.[br]5. Choose the "Circle" tool and select Circle with Center through Point. Use it to draw a circle whose center is your Circumcenter and which touches at least one [i]vertex[/i] of your triangle. [If your triangle is too big, you can zoom out by choosing the last tool on the row.][br]6. What do you notice about this circle? What does that mean about the distance from each vertex to the circumcenter?[br]7. On your paper, sketch a picture and fill in the blanks.
Circumcenter
Orthocenter
1. Draw a large triangle.[br]2. Choose the "Construct" tool and select Perpendicular Line. [br]3. Use the tool to create an altitude through each vertex that is perpendicular to the opposite side. [To do this, first select the vertex then select the side opposite from that vertex. Repeat for each vertex.][br]4.Use the "Point" tool to mark the intersection of your three lines.[br]5. Is it an equal distance from this point to each side? To each vertex? Measure each segment. Is there a common theme?[br]6. On your paper, sketch a picture and fill in the blanks.
Orthocenter

Information: Points of Concurrency