Identifying Rays

u07_l1_t1_we1 Identifying Rays

Identify all the rays shown in the image below.

and this is a reminder what a ray is.

A ray start at some point and then goes on forever in some direction.

In order to find a ray you need that point that you're starting off on

so let's that point over there is called X

and then you need another point that sits on the ray

and the ray is just keep going beyond, we

will name that point as "Y" and we will call the ray "XY"

It starts in "X" and keeps going in the direction of "y"

for ever, it crosses "y" and keeps going further

we need the second point to specify the direction

in which the ray is going.

So, lets identify all the rays shown in the image

below, we can start anywhere, we will start at

point J, the only line segment we have starting from J

is JH going up, goes upto H and keeps on going

in that direction beyond H, ray JH, starting from J

going through H and going beyond it forever

now if we go to H, there is no ray HJ as the line ends

in J and does not keep going beyond J, there is no

ray H as it is just one point, just usiing one point,

we cannot say it as a ray. now looking at our diagram

the only ray is JH. Now let us look at the other points.

If we look at point C, once again there is no point

after C to specify it as a ray, we can have a ray CE,

starts at C goes through E and goes on for ever,

you can also have a ray starting at C, going through F

and going on forever, CE & CF are the same rays

as F sits on ray CE and E sits of ray CF,

so CE & CF are the same rays,

now lets think about what we can do from point E,

We can start at point E , go in the direction of C

and go beyond C, so it is a ray, ray EC

you could start in E and go in the direction of A and go

beyond A, so EA is a ray, and we can start at E and

go in the direction of F and go beyond F, that is ray EF

ray EF and ray CF are different as the

starting points are different

Now lets go to point F. To the left of point F

there is no other point. We can look at the right,

we can have ray FE, start at F go through E and

beyond E, you can have ray FC, start at F

go through C and beyond C that is teh same thing as FE

ray FE and ray FC are the same as the point E

is on ray FC, then finally we have not focussed on point A

you may think there is ray AE, but the line does not

go beyond E, so it is not a ray, to the top of A

there is no other point, so there is no ray there either

that is all the rays based on the points specified.

If they had given us a point over there, we could have

had other rays,

There are 6 rays in this problem