Final answer:
A 45 degree line on a graph allows us to measure vertically whatever is on the horizontal axis. This line helps us understand the relationship between variables and allows us to easily measure one variable based on the other.
Step-by-step explanation:
A 45 degree line on a graph allows us to measure vertically whatever is on the horizontal axis. In mathematics, this line is often used to represent the concept of equality, where the values on both axes are equal. For example, if we have a graph where the horizontal axis represents time and the vertical axis represents distance, the 45 degree line would represent the situation where the distance traveled is equal to the time elapsed.
For instance, if we travel for 1 hour, the distance traveled would be equal to the time elapsed, which is 1 hour. If we travel for 2 hours, the distance traveled would be equal to 2 hours. This line helps us understand the relationship between the two variables and allows us to easily measure one variable based on the other.
Overall, the 45 degree line is an important tool in mathematics to visualize relationships between variables and understand the concept of equality.