-
Introduction
View the activity introduction for more information on the topic
-
Read aloud
Read the question aloud
-
Accessibility
Open the accessibility toolbar to change fonts and contrast, choose a different language, use a ruler and more
To find the length of a line segment, given the coordinates of its endpoints, we can use two methods.
Example
Find the length of the line segment AC whose endpoints are at:
A(-5, -3) and C(3, -3).
Method 1
Plot the points and count the squares.
This is a good method if you have time to do it and paper and pencil to hand!
AC is 8 units long. Just write 8
Method 2
If you don't have the time to plot the coordinates, this method is the best!
Subtract the relevant coordinates.
The x-coordinates of the endpoints of vertical lines will be the same.
The y-coordinates of the endpoints of horizontal lines will be the same.
A is at (-5, -3) and C is at (3, -3).
The line AC is horizontal because the y-coordinates are both -3.
Subtract the x-coordinates: -5 - 3 = -8 or 3 - -5 = 8.
Ignore the sign: -8 or 8 means a length of 8 units. Just write 8.
For vertical lines, we would subtract the y-coordinates.
Let's give it a try in some questions now.
Question
/ 10Mr Shepherd
Do you want to skip questions and finish?
Hold up, it looks like there may be an issue with your spelling. Why not try it again?
You need to check your answer before you proceed. Are you sure you want to skip?
Teacher explanation