Geometry how do you name a point??? more questions...?

Question

Alright: geometry homework sucks. and i need to know a few things that i cant seem to find in my book they may sound dumb but oh well I'm not the smartest...

What is the size of a point?

How do you name a point?

How do you name a line?

How do you name a plane?

How do you name a line segment?

What is rectangular coordinate system?

What is an XY graph?

What is a Cartesian coordinate system?

How would you graph a coordinate (-3,7) in the Cartesian plane?

Thanks!

Answer 1

> What is the size of a point?

A point has no size, or size 0.

It is just a location.

> How do you name a point?

Typically, you use one letter because there are fewer than

26 of them being discussed, and that is short and convenient.

Often just the beginning of the alphabet is used, as in the common phrase,

"Getting from point A to point B."

But you can use any name you like, such as Bob, "That thar' point over yonder", or Gxrflt.  But those are more cumbersome.

If you're talking about a whole lot of points,

then often numbers are used, P1, P2, ..., Pn.

> How do you name a line?

Like a point, it can be given any name you like.

L is common and then if there are just a few, adjacent letters

are used.

If a line is defined by two points with names,

then the combination, such as "line AB", might be used.

> How do you name a plane?

Same deal. Arbitrary name, single letter, or points or lines which define it.

> How do you name a line segment?

Usually by the end points.  AB, for example.

> What is rectangular coordinate system?

Points defined by their distance from two perpendicular lines,

which are called the axes (x-axis horizontal, y-axis vertical),

which intersect at a point identified by (0,0) [its distance from

each axis] and called the Origin.

> What is an XY graph?

A set of points, usually a line or a curve, through points

defined by their x- and y- coordinates, or distances from the axes.

> What is a Cartesian coordinate system?

Identify points by those distances.

> How would you graph a coordinate (-3,7) in the Cartesian plane?

Count over 3 units to the left on the horizontal or x-axis,

and 7 units up from there, parallel to the y-axis.

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