Fastest way to draw an isosceles trapezium?


Hi everybody

What way do you think it would be the fastest way to draw a isosceles trapezium (correct me if this is not the name) with specific dimensions?
I would be able to do it, but it would take me several steps, I think I’m making it hardest than it is.

Here a picture about the geometric shape I mean:

Thanks in advance.



Thank you @DaveR, you’re the fastest one, no doubt, but I’m interesting in that shape with specific dimensions, let’s say …
22,5mm for the top and 37,8mm for the bottom.

I could use some guidelines or temporary lines, but I guess there is a faster way.

EDIT: I got it, haha, sorry, I need to type the size when I’m moving the corner.

But I need to know what size I need to trim, right? I mean … basic maths are needed or can I type a value for the top length and keep it centered?


Best to use basic math.


ok :fu:


A non-math way would be to make two side by side rectangles, by starting to draw then typing in the width and height to finish the rectangle. Your left one might be 22.5mm by 37.8mm, and the right one would be 37.8mm by 37.8mm. Select the left one and use the Move tool and press the modifier key, to drag the bottom midpoint of the left rectangle to the bottom midpoint of the right rectangle.

By then it’s a bit of a mess, but if you group everything you can then use the line tool to draw the four lines you need, picking up from endpoints inside the group (which you delete when you’re done).


Thank you, it’s still faster than the way I would have done xD


Draw a rectangle. Make a copy of an edge and select that and the original edge. Then you can use the Scale tool. The Scale tool doesn’t unfortunately work with a single edge.


Nice trick Anssi :wink:


Woudn’t that still involve math, to know how much to scale to?


You can scale to exact dimensions by including units. No math required to do so.



That’s perfect @DaveR, good job, thank you so much.
I think it’s what colin meant.

About scaling … yeah, there are maths involved, but I didn’t know the trick of including a basic shape to scale a line.

I’m not sure if it’s possible to scale using tape measure tool, it ask me if I want to resize the entire model but I would be only interested in scaling certain shape.


Dave R would not give you the true length of AB and DC .You would have to draw circles of that radius from B and C and where they cross lines dropped from A and D would give you a trapesium with all known dimensions


He didn’t ask for the lengths of those sides.


He asked for specific dimensions


He only specified dimensions for the two parallel sides. A different method would be needed to make the angled sides a specified length, too.


Yeah, Dave R is right, I was only interested in the size for the top and bottom.
Anyway, I think It’s clear with Dave R method how to do it if you know all lenghts.


When giving all four lengths you have to be careful - not all combinations are possible!


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