TriangleDiv

by greatCar

HTML

<div style='position:relative;' class='arrow-up'></div>

<div style='position:relative; margin: 10px;' class='arrow-right'></div>

<div style='position:relative; margin: 10px;' class='arrow-left'></div>

CSS

.arrow-up {
  width: 0; 
  height: 0; 
  border-left: 3px solid transparent;
  border-right: 3px solid transparent;
  
  border-bottom: 8px solid black;
}

.arrow-up {
  width: 0; 
  height: 0; 
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  
  border-bottom: 5px solid black;
}

.arrow-down {
  width: 0; 
  height: 0; 
  border-left: 20px solid transparent;
  border-right: 20px solid transparent;
  
  border-top: 20px solid #f00;
}

.arrow-right {
  width: 0; 
  height: 0; 
  border-top: 2px solid transparent;
  border-bottom: 2px solid transparent;
  
  border-left: 10px solid green;
}

.arrow-left {
  width: 0; 
  height: 0; 
  border-top: 2px solid transparent;
  border-bottom: 2px solid transparent; 
  
  border-right:10px solid blue; 
}