純 CSS 繪制三角形（各種角度）

 轉載：https://www.cnblogs.com/lhb25/p/css-and-css3-triangle.html

 

 

 

Triangle Up

#triangle-up {
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-bottom: 100px solid red;
}

Triangle Down

#triangle-down {
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-top: 100px solid red;
}

Triangle Left

#triangle-left {
    width: 0;
    height: 0;
    border-top: 50px solid transparent;
    border-right: 100px solid red;
    border-bottom: 50px solid transparent;
}

Triangle Right

#triangle-right {
    width: 0;
    height: 0;
    border-top: 50px solid transparent;
    border-left: 100px solid red;
    border-bottom: 50px solid transparent;
}

Triangle Top Left

#triangle-topleft {
    width: 0;
    height: 0;
    border-top: 100px solid red;
    border-right: 100px solid transparent;
}

Triangle Top Right

#triangle-topright {
    width: 0;
    height: 0;
    border-top: 100px solid red;
    border-left: 100px solid transparent;
 
}

Triangle Bottom Left

#triangle-bottomleft {
    width: 0;
    height: 0;
    border-bottom: 100px solid red;
    border-right: 100px solid transparent;
}

Triangle Bottom Right

#triangle-bottomright {
    width: 0;
    height: 0;
    border-bottom: 100px solid red;
    border-left: 100px solid transparent;
}