Geometry
Line
A line is a straight path without thickness. It can be a straight path in any direction. Below are some lines
The arrows show that the lines can be extended in any direction
We can also name the lines. Let's call one end of the line A and the other and B.
AB is a line. We write it as \(\overleftrightarrow {AB}\)
Let's draw another line CD
You can see that \(\overleftrightarrow {CD}\) is smaller than \(\overleftrightarrow {AB}\)
A line segment is a part of a line and it has two endpoints
PQ is a line segment. We write It as \(\overline {PQ} \)
A ray is a part of a line that has one endpoint and extends in one direction without ending
XY is a ray. We write it as \(\overrightarrow {XY} \)
Let's measure the length of the line AB.
We can use a ruler to measure the length of the line.
Put your ruler over the line such that 0 of your ruler is at A. Mark the point where B is
Point B reads 9 cm 5 mm.
The length of the line is 9 cm and 5 mm