Newbie---Make a diamond with specific angles

The above script was unnecessarily bloated and lengthy. Here's a concise one, instead.

var degree1 = prompt("", 0, "Angle (degrees)"), side = 200;
var AR = app.activeDocument.artboards[0].artboardRect;
var d1 = 2*side*Math.cos((degree1/2)*(Math.PI/180));  // diagonal 1
var d2 = 2*side*Math.sin((degree1/2)*(Math.PI/180));  // diagonal 2
var rhombus = activeDocument.pathItems.add();
rhombus.setEntirePath( [ [ AR[2]/2, AR[3]/2+d1/2 ], [ AR[2]/2-d2/2, AR[3]/2 ], [ AR[2]/2, AR[3]/2-d1/2 ], [ AR[2]/2+d2/2, AR[3]/2 ], [ AR[2]/2, AR[3]/2+d1/2 ] ] );

Twice indeed, Kurt.

I also thought of an even sillier way including the deletion of Direction Handles.

I'm pretty sure that I had another similar and silly idea using an ellipse and the Anchor point tool, as you probably also had in mind, Jacob.

But perhaps it is still a good idea to listen to Len.

Indeed, Kurt.

And if this thread had gone from serious to silly as soon as there were a few usable answers, like so many did in the old days (I was tempted to come up with at least one way starting with the Ellipse Tool for the diamond here), Len would once more have said:

Back on Topic, please, Guys

In cases like that, Len Hewitt would certainly have said: "Guys, please keep it simple. Cheri told that he or she is a *beginner*!"

Some may still remember Len and some may not.

Here's a script to make a rhombus with an angle of your choosing.

var degree1 = prompt("Degrees", 0, "Angle"), degree2 = 180-degree1, a = 200;
var d = app.activeDocument.artboards[0].artboardRect;
var rect = app.activeDocument.pathItems.rectangle(d[3]/2+a/2, d[2]/2-a/2, a, a);
rect.rotate(45);
var p0 = rect.pathPoints[0], p2 = rect.pathPoints[2], p1 = rect.pathPoints[1], p3 = rect.pathPoints[3];
var W = Math.abs((p3.anchor[0]-p1.anchor[0])/2), H = Math.abs((p0.anchor[1]-p2.anchor[1])/2);
var d1 = 2*a*Math.cos((degree1/2)*(Math.PI/180)), d2 = 2*a*Math.sin((degree1/2)*(Math.PI/180));
var dx = W-d2/2, dy = d1/2-H;
p0.anchor = [ p0.anchor[0], p0.anchor[1]-dy ];
p0.rightDirection = [ p0.rightDirection[0], p0.rightDirection[1]-dy ];
p0.leftDirection = [ p0.leftDirection[0], p0.leftDirection[1]-dy ];
p2.anchor = [ p2.anchor[0], p2.anchor[1]+dy ];
p2.rightDirection = [ p2.rightDirection[0], p2.rightDirection[1]+dy ];
p2.leftDirection = [ p2.leftDirection[0], p2.leftDirection[1]+dy ];
p1.anchor = [ p1.anchor[0]+dx, p1.anchor[1] ];
p1.rightDirection = [ p1.rightDirection[0]+dx, p1.rightDirection[1] ];
p1.leftDirection = [ p1.leftDirection[0]+dx, p1.leftDirection[1] ];
p3.anchor = [ p3.anchor[0]-dx, p3.anchor[1] ];
p3.rightDirection = [ p3.rightDirection[0]-dx, p3.rightDirection[1] ];
p3.leftDirection = [ p3.leftDirection[0]-dx, p3.leftDirection[1] ];
redraw();

And another one.

Using the Appearance panel you can setup a Graphic style that can be applied later, you can then change the angle and the length of the line. I used a line with a fill and no stroke to avoid ending up with a diamond shape with 8 anchor points.

Cheri,

Or you can, Smart Guides still being your friends:

1) Use the Polar Grid Tool with 24 Radial Dividers (0 Concentric ones), then Delete the outer circle Group;

2) Alt/Option+ShiftClickDrag by one of the top Anchor Points right beside the middle topmost one to snap to the corresponding one at the bottom;

3) Ungroup everything down to individual paths and delete all the unwanted ones, then Join.

Edit: Hi Kurt. No show?

Below is the crucial step, Click Here to see in Chrome 

Cheri,

No thread is complete without a Line Tool way, especially if the desired size is the side length.

You can, Smart Guides still being your friends:

1) Click on the Artboard with the Line Tool and set the Length to the desired side length and set the angle to 75 degrees;

2) Object>Transform>Reflect a Copy Vertical axil;

3) ShiftClickDrag the top Anchor Point of the copy to snap to that of the original, and Join;

4) Object>Transform>Reflect a Copy Horizontal axis;

5) ShiftClickDrag one of the top Anchor Points of the copy to snap to that of the original, and Join.

Edit: Hi Peter, white for some days, a bit threadbare, only second time this very long autumn.

Below are the crucial steps for the Dodecagon and Line Tool ways; Click Here to see it in Chrome.