Help creating triangle in Coreldraw

[Brent Endsley]

I could use some help creating a triangle in coreldraw that is:
Side A = 13 in.
Side B = 9.25 in.
Side C = 5.5 in.

I have been trying, but can not seem to get it right. Thanks in advance for any help.

[Lee DeRaud]

Draw it the same way you would by hand:
1. Draw a 13" line.
2. Draw a 9.25" (radius) circle with the center at one end.
3. Draw a 5.5" (radius) circle with the center at the other end.
4. Draw a line from each end of the original line to the point whether the circles intersect. (Check your "snap to" settings if you're having trouble with this.)
5. Delete the circles.
6. (optional) Select the three lines and combine into a curve (ctrl-l, IIRC).

[Scott Shepherd]

Or just use this....

[Brent Endsley]

Perfect! Thanks for your help!

[Lee DeRaud]

Or just use this....Give a man a fish and he eats for a day.
Teach a man to fish...

[Scott Shepherd]

Teach a man to fish...

...and he takes your fishing job, you go unemployed and end up on the streets :D

Good explanation on how to draw it from scratch. I wasn't sure if he was looking to help in creating the file or understanding how to do it, I provided one, you provided the other, so no matter what he was looking for, he got it :)

[Mike Chance in Iowa]

While Lee's method is great, here's another option that will help you learn the features of Corel. I am going to over-simplify this to try to make it easy for all who are not used to working with Corel.

Draw a red horizontal line 13" long. (Use the Shift Key to keep it straight)
Draw a blue horizontal line 9.25" long.
Draw a green horizontal line 5.5" long.

Turn Snap to Objects on. (Alt + Z or View, Snap to Objects)

Select the green line. Select it again to Rotate/Skew. Move the Center Point to the left end of the line. It will snap to the node when you hover the mouse over it. While you still have the Rotate/Skew handles on the green line, hover the mouse over the right end until it turns into a rotate symbol (3/4 circle with arrows on each end at the top). Now click and rotate the green line up 1" so it is now at an angle. This does not change the size of the line. It only rotates it.
Select the green line again to remove the Rotate/Skew handles. Now hover your mouse over the left end and when it changes to a 4-way "move" arrow, click and drag the mouse and drop it over the left end of the red line.

Select the blue line. Select it again to Rotate/Skew. Move the Center Point to the right end of the line. While you still have the Rotate/Skew handles on the blue line, hover the mouse over the left end until it turns into a rotate symbol. Now click and rotate the blue line up 1" so it is now at an angle.
Select the blue line again to remove the Rotate/Skew handles. Now hover your mouse over the right end and when it changes to a 4-way "move" arrow, click and drag the mouse and drop it over the right end of the red line.

You now have the basics of the triangle. From this point on, select the green and blue lines and rotate them until their points meet. Make sure when you are rotating that you have the rotate symbol and not the skew symbol. The skew symbol is an up and down arrow and if you use that, it will change the length of your line.

Once you have the nodes snapped together, select all three lines and Arrange, Combine (Ctrl + L) to create one line. If you want to remove the extra nodes at the corners, using your Shape Tool, select the 2 nodes in a corner and press J on the keyboard to Join them or select the Join Two Nodes button on the toolbar.

[Lee DeRaud]

You now have the basics of the triangle. From this point on, select the green and blue lines and rotate them until their points meet.Am I the only one having trouble with this step? It obviously can't snap directly to the end node of the other line without changing the length. So every pass gets the two nodes a little closer, but never exactly the same point.

It's things like this that keep forcing me back to basic pencil-and-paper geometry when using Corel.

[Mike Chance in Iowa]

Am I the only one having trouble with this step? It obviously can't snap directly to the end node of the other line without changing the length. So every pass gets the two nodes a little closer, but never exactly the same point.


Sorry, I don't know what to say. It works for me. It will create an identical triangle as Scott's file that he uploaded.

[John Barton]

Does drawing a triangle as shown in this thread result in a cut piece that has the proper measurements? I will try it when I get to work.

Answer - yes dead perfect!!!

Now I just need to learn how to do the lines the way it was done in the triangle file. Going back to the front to review it. I tried to do it but I can't figure out how to attach the measuring lines to the regular lines. Also I am having trouble getting the apex to be exactly 5.5 and 9.25. Not really sure how to do that either.

But thank you for showing me something can be done that I thought was very difficult in Corel. I have always struggled with triangles for this reason.

- it's probably in the tutuorials as well :-)

[John Barton]

Or just use this....

Steve,

Can you teach me to fish? I'd like to know how you did your version with the linear dimensions tool.

I appreciate any help thanks.

John

[Michael Hunter]

I always use Lee's method of a line and two circles.
It's quick, easy, 100% accurate and you don't have to remember anything new or clever next time you need a triangle.


I wish that Corel had a "parallel-to-with-distance apart" command. My CAD program has this and I use it all the time. From two lines at right-angles, you can quickly build a "grid" with the exact dimensions for all the points on your drawing. Once the grid is completed the drawing is easy and accurate (using snap-to-intersections).
I know that I could simulate this with the copy and nudge commands, but it is long-winded compared to the CAD way. If Corel had this I could bin the CAD program completely.

[Scott Shepherd]

Steve,

Can you teach me to fish? I'd like to know how you did your version with the linear dimensions tool.

I appreciate any help thanks.

John

Hi John, I'm afraid I didn't use any neat, nifty drawing tricks, I used Trig to find out the angles and then I drew it from there. Since I knew the length of the lines and the angles, I just drew the lines the right length and rotated them to the angle needed.

For the dimensions, I just used the dimension tool and snapped to the ends.

I think Lee's method is probably the easiest to learn and remember.

Wish I had a great trick for it, but this case was just pure math.

[Ross Moshinsky]

Lee's method is how a drafter would do it. It is the easiest & fastest method. I've done a good bit of drafting in various high level cad programs and there were a few people who did the "nudge and rotate" method on various things. For the most part, it works, BUT if you zoom in a ridiculous amount, you'll notice imperfections. Another issue comes if you want to join the lines and make a path, it may not join because there is too much of a gap. This can become a very annoying issue that you'll waste hours trying to correct.

The only other precise method I can think of is basically breaking the triangle into two right triangles. Then using trig and the Pythagorean theorem to figure things out. This will take a lot longer. I'm sure there are a few online calculators to minimize the hand work, but in the end, it's more complicated.

[Scott Shepherd]

Then using trig and the Pythagorean theorem to figure things out. This will take a lot longer. I'm sure there are a few online calculators to minimize the hand work, but in the end, it's more complicated.

I used an application on my phone. Plugged the 3 sides in, it gave me all the angles. Took about 30 seconds :)

[Lee DeRaud]

I used Trig to find out the angles and then I drew it from there. Since I knew the length of the lines and the angles, I just drew the lines the right length and rotated them to the angle needed.Ah. This is the kind of thing that tweaks my accuracy fetish: a trig/numerical solution is certainly good enough for any application being discussed here, but it's only accurate to the limits of your computations and angle entry. (Not to mention that, at my age, I have to look up the law-of-cosines formula every time I need it.:p)

The geometric solution is exact...in theory. It is itself limited to the accuracy of Corel's internal computation of the intersection points, but I can wave my hands and ignore petty issues like that. :cool:

(Vaguely relevent side question: will Corel accept arbitrary expressions like "acos(0.xxxx)" as angle entries? I know simple expressions work...)

[Lee DeRaud]

I used an application on my phone. Plugged the 3 sides in, it gave me all the angles. Took about 30 seconds :)The world is devolving to the point where the solution for every problem will begin, "Step 1: Buy an app." :eek:

[Scott Shepherd]

If it makes you feel any better, I did do it longhand afterwards just to make sure I still could :)

I agree, it's not 100% accurate, but like you said, it's far close enough for anything any of us will be doing with the laser.

[John Barton]

If it makes you feel any better, I did do it longhand afterwards just to make sure I still could :)

I agree, it's not 100% accurate, but like you said, it's far close enough for anything any of us will be doing with the laser.

Well I can't do it long hand - my teacher did warn me every time she woke me up that I would need to know this someday.

Here is a website that helps to figure the angles and lengths.
http://www.1728.com/trig4.htm

I don't really understand why Corel can't put such a calculator in the program. Wouldn't it be great if we could just input the values and it spits out the triangle you want?

FWIW the one you drew came out perfect when I cut it.