<div class="logo">
  <div class="r">R</div>
  <div class="star"></div>
</div>

:root {
  --yellow: #ffad00;
  --black: #000;
  --white: #fff;
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
*::before,
*::after {
  box-sizing: border-box;
  content: '';
  position: absolute;
}
body {
  display: grid;
  place-items: center;
  min-height: 100vh;
}
.logo {
  width: 60vmin;
  height: 60vmin;
  background-color: var(--yellow);
  border-radius: 10vmin;
  border: 1.5vmin solid var(--black);
}
.r {
  font-family: Helvetica;
  font-weight: bold;
  font-style: italic;
  font-size: 40vmin;
  position: relative;
  left: 12vmin;
}
.star,
.star::before,
.star::after {
  width: 0;
  height: 0;
}
.star {
  border-left: 4vmin solid transparent;
  border-right: 4vmin solid transparent;
  border-bottom: 6vmin solid var(--white);
  position: relative;
  top: -14vmin;
  left: 39.5vmin;
}
.star::before {
  border-left: 10vmin solid transparent;
  border-right: 10vmin solid transparent;
  border-bottom: 7vmin solid var(--white);
  transform: rotate(-32deg);
  left: -10vmin;
  top: 4vmin;
}
.star::after {
  border-left: 10vmin solid transparent;
  border-right: 10vmin solid transparent;
  border-bottom: 7vmin solid var(--white);
  transform: rotate(32deg);
  left: -10vmin;
  top: 4vmin;
}