用css写三角

复制代码代码以下:

#triangle-up:after {

content: '';
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-bottom: 100px solid red;
}

复制代码代码以下:

#triangle-down:after {

content: '';
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-top: 100px solid red;
}

 

复制代码代码以下:

#triangle-left:after {

content: '';
    width: 0;
    height: 0;
    border-top: 50px solid transparent;
    border-right: 100px solid red;
    border-bottom: 50px solid transparent;
}

 

复制代码代码以下:

#triangle-right:after {

content: '';
    width: 0;
    height: 0;
    border-top: 50px solid transparent;
    border-left: 100px solid red;
    border-bottom: 50px solid transparent;
}

 

复制代码代码以下:

#triangle-topleft:after{

content: '';
    width: 0;
    height: 0;
    border-top: 100px solid red;
    border-right: 100px solid transparent;
}

 

复制代码代码以下:

#triangle-topright:after {

content: '';
    width: 0;
    height: 0;
    border-top: 100px solid red;
    border-left: 100px solid transparent; 
}

 

复制代码代码以下:

#triangle-bottomleft:after {

content: '';
    width: 0;
    height: 0;
    border-bottom: 100px solid red;
    border-right: 100px solid transparent;
}

 

复制代码代码以下:

#triangle-bottomright:after {

content: '';     width: 0;     height: 0;     border-bottom: 100px solid red;     border-left: 100px solid transparent; }