Add and Subtract Line Segments
Now that you know how to copy a line segment, you can add and subtract line segments to create new segments (using the Segment Addition Postulate).
The top red line is equal to AB + CD.
The bottom red line is equal to AB - CD.
Verify you have added and subtracted correctly by using the Segment Measure tool
and checking your work with a calculator.
and checking your work with a calculator.