ACT Prep: Estimating Line Segment Lengths

What is the length of line segment $$PR$$ if line segment $$PQ$$ is 7 cm and line segment $$QR$$ is 5 cm, with points $$P$$ , $$Q$$ , and $$R$$ being collinear?

If line segment $$KL$$ is 10 cm and line segment $$LM$$ is 15 cm, what is the length of line segment $$KM$$ if $$K$$ , $$L$$ , and $$M$$ are collinear?

What is the length of line segment $$AC$$ if line segment $$AB$$ is 5 cm and line segment $$BC$$ is 7 cm, with $$AC$$ being a straight line?

If line segment $$ST$$ is represented in a figure, how do you determine its length?

Define collinear points.

What is the formula to find the length of a line segment between two points on a number line?

If the total length of line segments $$PQ$$ and $$QR$$ is 12 cm, what can you infer about the lengths of $$PQ$$ and $$QR$$ ?

What is the significance of measuring line segments in geometry?

How do you estimate the length of a line segment when exact measurements are not available?

What is the relationship between the lengths of collinear segments?