100
Measuring segments
Textbook Part 3, pp. 54–55
GoalMeasure a segment correctly with a ruler (starting from 0) and label it with letters.
New words
length of a segment · kesma uzunligithe 0 mark · 0 belgisisegment AB · AB kesma
Explanation
A segment’s ends are marked with points: A and B. To measure, put the ruler’s 0 mark on point A and read the number at point B. That number is the length of segment AB: AB = 6 cm.
Worked examples
The first segment is 5 cm and the second is 7 cm longer: 5 + 7 = 12 cm.
A traffic-light picture is 8 cm tall. A segment 2 cm longer: 10 cm.
Class activity
Rope experiment: cut a piece from the middle of a rope. Does it have a start and an end? (Yes — it is a segment.) Children measure the piece with a ruler.
Practice
1
Which ruler mark do you start measuring from?
0
2
AB = 4 cm and CD is 3 cm longer. CD = ?
7 cm
3
12 cm − 5 cm = ?
7 cm
4
Draw a 9 cm segment in your notebook and label it MN.
M •———— 9 cm ————• N