<h1 class="cp_h1title">見出しテキスト</h1>

.cp_h1title {
  position: relative;
  color: #E65100;
  background: #F9A825;
}
.cp_h1title::before,
.cp_h1title::after {
  position: absolute;
  content: '';
  border-style: solid;
  border-color: transparent;
}
.cp_h1title::before {
  top: 100%;
  left: 0;
  border-width: 0 15px 15px 0;
  border-right-color: #F57F17;
}
.cp_h1title::after {
  top: 0;
  right: 0;
  border-width: 25px 20px;
  border-right-color: #fafcfc;/*背景色で右のリボンを再現*/
}