Is there an easier way to draw a parallelogram aligned with a triangle?

Question

I'm trying to draw two shapes in Adobe Illustrator CS4, but in a somewhat abnormal position.

I've attached an image of the desired effect I'm trying to achieve, and I've obviously gotten there, but my way feels clunky and I'm wondering if there's a better mechanism to do it. (Do note, this is my first Illustrator project ever.)

I want to draw a triangle, and then on the top-right edge I want a rectangle rotated and skewed so that the bottom-left corner is above and parallel to the top-right edge of the triangle, and the top-left edge of the rectangle (which is a parallelogram at this point) is coincident with but not in the same position as the top-left edge of the triangle.

My current method is to create a "Guidelines" layer, where I draw an equilateral triangle and convert it to a Guide. Then I draw the triangle and place it, then draw the rectangle and right-click → transform → rotate 60 degrees, then position and size it to where I hope it belongs, as I want the bottom corner of the parallelogram in vertical alignment with the right corner of the triangle, and then shear it at -150 degrees, along the 60 degree angle axis.

Then I free-hand move each corner until everything "looks right", which involves many instants of trial-and-error, and I get an imperfect result.

This seems like a lot of free-handing, because when I try to resize the parallelogram (if I shear first before positioning) it becomes very much skewed, I would like to maintain the angles of it, as they work with my intentions.

I've hand-drawn the red vertical line to indicate the intended alignment at that corner, the guides should indicate the desired effect with the remainder of the alignments, though they're not perfect. I would prefer the resultant shape to be perfectly aligned into my guide-lines, but freehanding it worked good enough.

Answer 1

Using the Pathfinder Panel (for CS4 or newer)

This will work in versions earlier than CS4 as well, as long as the version has the Pathfinder Panel (circa AI8 I think). The difference is prior to CS4 you need to hold down the Option/Alt key before clicking the Minus Front button in the last step.

• Base triangle
• Direct Selection Tool, hold the Option/Alt and Shift to duplicate and copy it offset down and to the right. Defines the width of the parallelogram. Shift ensures you move the triangle at a 45° angle based on the constrain preferences of the app, if you've changed those, you may need to reset them.
• Copy base triangle, Paste in Front, Scale to desired final triangle size.
• Copy smaller triangle, Paste in Front, scale up to define the gap between the two final shapes
• Select everything except the small final triangle
• Hit the Minus Front Button on the Pathfinder Panel

Using the Shape Builder Tool for CS6+

• Same overall set up as above
• Select All, grab the Shape Builder Tool. Hold the Option/Alt key down and drag across pieces to remove.
• Still using the Shape Builder tool, let go of the modifier key and drag across pieces to combine
• Remove the extra anchor point caused by using Shape Builder.

Answer 2

I think you are making this too complicated.

Start with the triangle, and draw guides. Duplicate those you need at the same angle and place them where you want. They will be parallel because they are simply duplicates. Add a vertical line at the right corner of the triangle.

Then when you have finished use the Pen Tool to create the parallelogram, with Smart Guides enabled. Hopefully you will get the idea from the example below.

Answer 3

I have a better idea.

Menu > Shapes > Add Shape >

Triangle Square Rectangle Parallelogram Dodecahedron 100 other shapes.

I mean this is a COMPUTER I am using.