1-2
Use with Lesson 1-2
Explore Properties Associated with Points The two endpoints of a segment determine its length. Other points on the segment are between the endpoints. Only one of these points is the midpoint of the segment. In this lab, you will use geometry software to measure lengths of segments and explore properties of points on segments.
Activity
KEYWORD: MG7 Lab1
1 Construct a segment and label its endpoints A and C.
2
̶̶ Create point B on AC.
3 Measure the distances from A to B and from B to C. Use the Calculate tool to calculate the sum of AB and BC. ̶̶ 4 Measure the length of AC. What do you notice about this length compared with the measurements found in Step 3? ̶̶ 5 Drag point B along AC. Drag one of the endpoints ̶̶ of AC. What relationships do you think are true about the three measurements? ̶̶ 6 Construct the midpoint of AC and label it M. ̶̶̶ ̶̶̶ 7 Measure AM and MC. What relationships do you ̶̶ ̶̶̶ ̶̶̶ think are true about the lengths of AC, AM, and MC ? Use the Calculate tool to confirm your findings. ̶̶ 8 How many midpoints of AC exist?
Try This 1. Repeat the activity with a new segment. Drag each of the points in your figure (the endpoints, the point on the segment, and the midpoint). Write down any relationships you observe about the measurements. ̶̶ ̶̶ ̶̶ ̶̶ 2. Create a point D not on AC. Measure AD, DC, and AC. Does AD + DC = AC? What do you think has to be true about D for the relationship to always be true? 12
Chapter 1 Foundations for Geometry