Untitled

.box {
  width: 700px;
  height: 250px;
  margin: 40px auto 0 auto;
  background: transparent;
  border-radius: 48px 48px 0 0;
  border-top: 1px solid #33CC66;
  border-left: 1px solid #33CC66;
  border-right: 1px solid #33CC66;
  position: relative;
}

.box::before {
  content: '';
  width: 0;
  height: 0;
  background: transparent;
  border-left: 0 solid transparent;
  border-bottom: 60px solid transparent;
  border-right: 60px solid transparent;
  border-top: 0px solid transparent;
  background: url('https://i.ibb.co/jGmnB6h/left-pointer.png') 0 0 no-repeat;
  background-size: 40px auto;
}

.box::after {
  content: '';
  width: 0;
  height: 0;
  background: transparent;
  border-left: 0 solid transparent;
  border-bottom: 60px solid transparent;
  border-right: 60px solid transparent;
  border-top: 0px solid transparent;
  background: url('https://i.ibb.co/W52sc6D/right-pointer.png') 0 0 no-repeat;
  background-size: 40px auto;
}


.box::before, .box::after {
  position: absolute;
  top: -37px;
}

.box::after {
  left: 48.5%;
}

.box::before {
  right: 48.5%;
}