transform-origin

<div class="grid">
  <div class="col">
    <div class="row">
      <div class="cell">
        rotate(<span class="angle">-120</span>deg);
        <div class="border">
          <div class="content">
            <div class="center"></div>
            <div class="tr d2"></div>
          </div>
        </div>
      </div>
      <div class="cell">
        rotatex(<span class="angle">-120</span>deg);
        <div class="border">
          <div class="content">
            <div class="center"></div>
            <div class="tr d3x"></div>
          </div>
        </div>
      </div>
      <div class="cell">
        rotatey(<span class="angle">-120</span>deg);
        <div class="border">
          <div class="content">
            <div class="center"></div>
            <div class="tr d3y"></div>
          </div>
        </div>
      </div>
      <div class="cell">
        rotatez(<span class="angle">-120</span>deg);
        <div class="border">
          <div class="content">
            <div class="center"></div>
            <div class="tr d3z"></div>
          </div>
        </div>
      </div>
    </div>
    <div class="cell note">
      transform-origin: <input type="text" value="30% top -20px"> (<i>rotate by <input type="number" min="-360" max="360" value="-120"> deg</i>)
    </div>
  </div>
</div>

html,body {
  height: 100%;
  box-sizing: border-box;
}

.grid {
  width: 100%;
  height: 100%;
  display: flex;
  background: #EEE;
  font: 1em monospace;
}

.row {
  display: flex;
  flex: 1 auto;
  flex-direction: row;
  flex-wrap: wrap;
  justify-content: space-between;
}

.col {
  display: flex;
  flex: 1 auto;
  flex-direction: column;
}

.cell {
  box-sizing: border-box;
  margin: .5em;
  padding: .5em;
  background-color: #FFF;
  overflow: hidden;
  text-align: center;
}

.note {
  background: #fff3d4;
  padding: 1em;
  margin: 0 .5em .5em;
  font: .8em sans-serif;
  text-align: center;
  flex: none;
}

input[type=number] {
  width: 3rem;
}

.border {
  width : 140px;
  height: 140px;
  border: 1px solid #E4F0F5;
  margin: .5rem auto;
  overflow: hidden;
}

.content {
  width : 50px;
  height: 50px;
  margin: 44px;
  border: 1px dotted hsla(0, 100%, 50%, .5);
  position: relative;
}

.center {
  position: absolute;
  width : 5px;
  height: 5px;
  border-radius: 100%;
  background: red;
  top : 50%;
  left: 50%;
  transform: translate(-3px, -3px);
  z-index: 1;
}

.center:before {
  content: '';
  position: absolute;
  left  : 2px;
  right : 2px;
  top   : -6px;
  bottom: -6px;
  background: red;
}

.center:after {
  content: '';
  position: absolute;
  left  : -6px;
  right : -6px;
  top   : 2px;
  bottom: 2px;
  background: red;
}

.tr {
  width : 50px;
  height: 50px;
  background: hsla(215, 100%, 50%, 0.3);
  transition: transform 2s linear;
}

.tr.d2  { transform: rotate(-120deg);  }
.tr.d3x { transform: rotatex(-120deg); }
.tr.d3y { transform: rotatey(-120deg); }
.tr.d3z { transform: rotatez(-120deg); }

window.addEventListener('load', function () {
  var LENGTH = /^-?\d+(?:em|ex|cap|ch|ic|rem|lh|rlh|vh|vw|vi|vb|vmin|vmax|px|mm|q|cm|in|pt|pc$)/
  var LENGTH_PERCENT = /^-?\d+(?:em|ex|cap|ch|ic|rem|lh|rlh|vh|vw|vi|vb|vmin|vmax|px|mm|q|cm|in|pt|pc|%$)/

  var KEYX = /^left|center|right$/
  var KEYY = /^top|center|bottom$/
  var KEYALL = /^left|center|right|top|bottom$/

  var INPUT = document.querySelector('input[type=text]')
  var ANGLE = document.querySelector('input[type=number]')
  var CENTER= Array.from(document.querySelectorAll('.center'))
  var TR    = Array.from(document.querySelectorAll('.tr'))

  function update () {
    INPUT.style.boxShadow = 'none'
    var val  = INPUT.value.trim()
    var isValid = true
    var v = val.split(/\s+/)

    isValid = isValid && (v[2] === undefined || LENGTH.test(v[2]))
    isValid = isValid && (v[1] === undefined || LENGTH_PERCENT.test(v[1]) || KEYALL.test(v[1]))
    isValid = isValid && (LENGTH_PERCENT.test(v[0]) || KEYALL.test(v[0]))

    if (v.length === 2) {
      var double_key_words = KEYY.test(v[0]) && KEYX.test(v[1])
      var ordinary_value = (LENGTH_PERCENT.test(v[0]) || KEYX.test(v[0])) && (LENGTH_PERCENT.test(v[1]) || KEYY.test(v[1]))

      isValid = isValid && (double_key_words || ordinary_value)
    }


    if (!isValid) {
      val = '50% 50%'

      if (v[0] !== '') {
        INPUT.style.boxShadow = '0 0 .5em red'
      }
    }

    TR.forEach(function (tr, index) {
      tr.style.transformOrigin = val;

      setTimeout(function () {
        var pos = window.getComputedStyle(tr).transformOrigin.split(/\s+/);

        CENTER[index].style.left = pos[0]
        CENTER[index].style.top  = pos[1]
      }, 0)
    })
  }

  function rotate() {
    var value = Math.min(360, Math.max(-360, Number(ANGLE.value) || 0));

    document.querySelector('.d2').style.transform = 'rotate(' + value + 'deg)'
    document.querySelector('.d3x').style.transform = 'rotatex(' + value + 'deg)'
    document.querySelector('.d3y').style.transform = 'rotatey(' + value + 'deg)'
    document.querySelector('.d3z').style.transform = 'rotatez(' + value + 'deg)'
    Array.from(document.querySelectorAll('.angle')).forEach(function (node){
      node.innerText = value
    })
  }

  function mouseenter() {
    document.querySelector('.tr.d2' ).style.transform = 'rotate(0)'
    document.querySelector('.tr.d3x').style.transform = 'rotatex(0)'
    document.querySelector('.tr.d3y').style.transform = 'rotatey(0)'
    document.querySelector('.tr.d3z').style.transform = 'rotatez(0)'
  }

  INPUT.addEventListener('input', update)
  ANGLE.addEventListener('input', rotate)
  update()
  rotate()

  document.querySelector('.row').addEventListener('mouseenter', mouseenter)
  document.querySelector('.row').addEventListener('mouseleave', rotate)
})