<iframe 
    src="http://jsxgraph.org/share/iframe/demo-ex-8-1" 
    style="border: 1px solid black; overflow: hidden; width: 550px; aspect-ratio: 55 / 65;" 
    name="JSXGraph example: Parallelogram" 
    allowfullscreen
></iframe>

<div id="board-0-wrapper" class="jxgbox-wrapper " style="width: 100%; ">
   <div id="board-0" class="jxgbox" style="aspect-ratio: 1 / 1; width: 100%;" data-ar="1 / 1"></div>
</div>

<script type = "text/javascript"> 
    /*
    This example is not licensed.
    */
    
    const BOARDID = 'board-0';

    JXG.Options.label.autoPosition = true;
    JXG.Options.text.useMathJax = true;
    JXG.Options.text.fontSize = 20;
    
    const board = JXG.JSXGraph.initBoard(BOARDID, {
        boundingbox: [-5, 5, 5, -5],
        showNavigation: false,
        keepaspectratio: true
    });
    
    let p = board.create('point', [-3, -3], {name: '\\(p\\)'});
    let q = board.create('point', [2, -3], {name: '\\(q\\)'});
    let s = board.create('point', [-1, 1], {name: '\\(s\\)'});
    let r = board.create('parallelpoint', [p, q, s], {name: '\\(r\\)', color: 'blue'});
    
    let pq = board.create('arrow', [p, q], {
        withLabel: true,
        name: '\\(\\vec{pq}\\)',
        label: {position: 'top', parse: false},
        lastArrow: {type: 4, size: 8}
    });
    let sr = board.create('arrow', [s, r], {
        withLabel: true,
        name: '\\(\\vec{sr}\\)',
        label: {position: 'top', parse: false},
        lastArrow: {type: 4, size: 8}
    });
    let ps = board.create('arrow', [p, s], {
        withLabel: true,
        name: '\\(\\vec{ps}\\)',
        label: {position: 'top'},
        lastArrow: {type: 4, size: 8}
    });
    let qr = board.create('arrow', [q, r], {
        withLabel: true,
        name: '\\(\\vec{qr}\\)',
        label: {position: 'top'},
        lastArrow: {type: 4, size: 8}
    });
    
    let pr = board.create('arrow', [p, r], {});
 </script> 

<jsxgraph width="100%" aspect-ratio="1 / 1" title="Parallelogram" description="This construction was copied from JSXGraph examples database: BTW HERE SHOULD BE A GENERATED LINKuseGlobalJS="false">
   /*
   This example is not licensed.
   */
   
   JXG.Options.label.autoPosition = true;
   JXG.Options.text.useMathJax = true;
   JXG.Options.text.fontSize = 20;
   
   const board = JXG.JSXGraph.initBoard(BOARDID, {
       boundingbox: [-5, 5, 5, -5],
       showNavigation: false,
       keepaspectratio: true
   });
   
   let p = board.create('point', [-3, -3], {name: '\\(p\\)'});
   let q = board.create('point', [2, -3], {name: '\\(q\\)'});
   let s = board.create('point', [-1, 1], {name: '\\(s\\)'});
   let r = board.create('parallelpoint', [p, q, s], {name: '\\(r\\)', color: 'blue'});
   
   let pq = board.create('arrow', [p, q], {
       withLabel: true,
       name: '\\(\\vec{pq}\\)',
       label: {position: 'top', parse: false},
       lastArrow: {type: 4, size: 8}
   });
   let sr = board.create('arrow', [s, r], {
       withLabel: true,
       name: '\\(\\vec{sr}\\)',
       label: {position: 'top', parse: false},
       lastArrow: {type: 4, size: 8}
   });
   let ps = board.create('arrow', [p, s], {
       withLabel: true,
       name: '\\(\\vec{ps}\\)',
       label: {position: 'top'},
       lastArrow: {type: 4, size: 8}
   });
   let qr = board.create('arrow', [q, r], {
       withLabel: true,
       name: '\\(\\vec{qr}\\)',
       label: {position: 'top'},
       lastArrow: {type: 4, size: 8}
   });
   
   let pr = board.create('arrow', [p, r], {});
</jsxgraph>