# How to enter dimensions

If I’m making a rectangle for a tabletop, how do I enter in the dimensions 36" x 72" into the command bar? Or is this not the way it’s done in Rhino?

Hi Pilip, start the _Rectangle command then pick a first corner point, then when it asks for the other corner you can enter width, height. Does that help ? Btw. please assign a cathegory to your posts.

c.

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Will do. Thanks for the responses.

Philip, just to expand on Clement’s answer, if you click 0,0 for the first point, and 36, 72 for the second, you will get the rectangle you want. However you are entering the coordinates of the points, not the dimension of the rectangle. So if you click on a point other than 0,0 for the first point you won’t get the correct size.
To ensure that the rectangle is correct, no matter where the first point is, you have to use “relative coordinates” which count from the first point and not from 0,0.
You might want to check out a tutorial to understand this better than I’m explaining it!
Nick

likewise, you may find `_Rectangle` 3 point option a more viable solution…

that’s the one i usually always use and it’s the macro i have assigned to my keystroke…
it’s an extra click but at the same time, it offers more control over direction/orientation of a rectangle as well as being less confusing about which of the two dimensions is going to go on which axis…

personal preference of mine but you may want to try it out.

Hey Nick, thanks for clarifying that. So is it possible to use inches for the commands? Or will I always need to use coordinate points? If so, how do they translate to inches?

Sorry for all the questions, I haven’t been able to find a tutorial on this specific issue. I’ve also been using sketchup for the past couple of years, so this is completely new to me.

Thanks,
Philip

this works the same way it does in sketchup… if your model units are set to inches then you only have to type the numbers 24,48… if your model units are set to inches and you want to use feet, you have to signify that 24’,48’ (or 24mm,48mm etc…)

the difference with sketchup is that it defaults to relative coordinates instead of the plane’s coordinates…

so you have to signify you’ll be using relative coordinates via the use of the letter ‘r’

in your top post example, use a template with units in inches, start the rectangle command, click the cursor at the first point of the rectangle, type r36,72 `<enter>`

or if your units aren’t inches, type r36",72" `<enter>`

Don’t forget that after setting the first point - either by click or coordinate entry - that if you type in a single numerical value (not a coordinate triplet, no"r" necessary) and Enter, it will be considered as a length value along the current CPlane from the first point; and a second value will be taken as the width. With Box, you can also enter the height.

– Mitch

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oh… I didn’t realize you could do it like that.

I got hung up on making the sketchup comparison in which you have to enter x,y in order for it to work.

this sounds better though.

If you read the command line, it gives you that info…

Command: _Rectangle
First corner of rectangle ( 3Point  Vertical  Center  Rounded ):
Other corner or length ( 3Point  Rounded ): 20
Width. Press Enter to use length ( 3Point  Rounded ): 10

And note if you just hit Enter after entering the length it gives you a square (width=length).

A cube is Box, Corner, SideLength, Enter Enter

–Mitch

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nice… just tried what you’re saying and yeah, that’s better than the way i was using the rectangle (and box) command and it’s similar to how i would use 3point (ie- no need to use relative coordinates) only more streamlined…

also just realized the shift key gives a square constraint which is another one i’ll be able to make use of in the standard rectangle command (since you can snap to other geometry instead of entering dimensions and still get a square)

Thanks again guys… Not sure why that was stumping me… Good call going with the box, Helvettosaur… Saves me a few steps.

This thread was very helpful to me. I’d like to build on it for future searches.

What do I do if I want to later re-size the surface (or, say, one dimension of a 3-D object) to a specific size.

Examples:

1. I make the table top as described in this thread: starts a rectangle, types r36,72, enter.
Now I want to change the 72 dim to 70. How do I do that?

2. I make a cube (polysurface) that measures 3 x 3 x 3. I want to change one dim to 2.75. How do I do that?

I’ve tried _MoveEdge and entering -.25, but the change is not -.25"…

What you want is MoveFace not MoveEdge. With units set to inches, enter the command, select the face. When prompted for the move from point, snap to any point on the edge of the face, move the mouse in the direction you want to move the face, enter 1/4", hit Enter.

When working with feet and inches in Rhino I’ve always set my units as inches and simply entered dimensions just as I would in AutoCAD. For example: let’s say I want to draw a 2D rectangle 56-1/4" wide by 36" long working in Top View. With my units set to inches I click the rectangle button. When it asks for a starting point I type 0,0,0 (Old habit that assures me that I’m starting at Z=0 on the current C-plane.) When asked for the opposite corner I type 56-1/4", 36" and hit Enter. Rhino will automatically convert the fraction part of the first dimension to a decimal, and place the corner at the correct point. IIRC, you could alternatively enter these dimensions as 4’ 8-1/4", 3’ and Rhino will still take care of the math automatically.

This is one of the things I’ve always loved about Rhino. Makes it easy to bounce back and forth between Rhino and AutoCAD without changing the method of entering coordinates.

You enter relative coordinates in the same manner but, like AutoCAD, Rhino has to know that the coordinates are relative. It’s all about @. For example: I want to draw another rectangle, 23-3/4" wide by 18-3/16" long from the midpoint of the top of the previous rectangle. I click the Rectangle button. When asked for the start point I snap to the midpoint of the top of the previous rectangle. When asked for the opposite corner I type @23-3/4", 18-3/16" and hit Enter. Again, Rhino automatically converts the fractions to decimals and places the opposite corner at the correct point. The @ symbol tells Rhino that my coordinates are relative to the start point, not 0,0.

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To add to what Frank said;

1. Instead of typing 0,0,0 for the origin, just type 0 and hit enter.

2. Sub-Object selection works great here, especially if your Grid Snap Spacing is set to an interval you often work with (in this case, 1/4" or 1/8"). Control-Shift and pick the face you want to move, then just drag and watch the status line to get the right snap point.

3. Another easy way is to use 1D Scale. Invoke the command, select the object, click on the opposite side from the one you want to shorten/lengthen to set a base point, click on the side you want to move to establish the span you want to change, type the new length (70 or 2.75 in your examples), and hit enter and it will adjust the span to the new measurement. I like this way best because I don’t even have to know what the current size is or the distance I want to move the face, only the final dimension I want. Nor does it care whether the object is oriented to any of the c-planes, it just wants the start and end points of a span and the dimension you want the span to be.