círculo CSS
#circle {
width: 100px;
height: 100px;
background: red;
border-radius: 50%
}
Combative Cowfish
#circle {
width: 100px;
height: 100px;
background: red;
border-radius: 50%
}
.triangle{
border-left: 5px solid transparent;
border-right: 5px solid transparent;
border-bottom: 5px solid red;
border-width:100px;
}#triangle {
width: 0;
height: 0;
border-left: 18px solid transparent;
border-right: 18px solid transparent;
border-bottom: 30px solid blue;
}div {
clip-path: polygon(100% 100%, 100% 100%, 100% 100%)
}#triangle-up {
width: 0;
height: 0;
border-left: 50px solid transparent;
border-right: 50px solid transparent;
border-bottom: 100px solid red;
}