Final answer:
To find the length of segment BC, subtract the length of segment AB (calculated by subtracting AC from AD) from BD. The length of BC is 6 units.
Step-by-step explanation:
The student has asked a question about determining the length of segment BC given other segment lengths in a line. To solve this, we need to understand the properties of segments on a line.
Let's consider the four points A, B, C, and D on a line with given distances between some pairs:
- Segment AC = 13 units
- Segment BD = 14 units
- Segment AD = 21 units
To find the length of segment BC, we need to use the fact that AD (the entire length) is equal to the sum of segments AB, BC, and CD.
Because A, B, C, and D are in that order on the line, segment AD is composed of segments AB, BC, and CD. Hence, segment AB can be represented as AD minus AC, which is 21 - 13 = 8 units. Now, BD is composed of AB and BC, so if we subtract AB from BD, we get BC. Thus, BC = BD - AB = 14 - 8 = 6 units.
Therefore, the length of BC is 6 units.