css绘制向左三角形_CSS 实现绘制各种三角形

一、前言

三角形实现原理：宽度width为0；height为0；(1)有一条横竖边(上下左右)的设置为border-方向：长度 solid red，这个画的就是底部的直线。其他边使用border-方向：长度 solid transparent。(2)有两个横竖边(上下左右)的设置，若斜边是在三角形的右边，这时候设置top或bottom的直线，和右边的斜线。若斜边是在三角形的左边，这时候设置top或bottom的直线，和左边的斜线。

二、实现

2.1 Triangle Up

#triangle-up {

width: 0;

height: 0;

border-left: 50px solid transparent;

border-right: 50px solid transparent;

border-bottom: 100px solid red;

}

2.2 Triangle Down

#triangle-down {

width: 0;

height: 0;

border-left: 50px solid transparent;

border-right: 50px solid transparent;

border-top: 100px solid red;

}

2.3 Triangle Left

#triangle-left {

width: 0;

height: 0;

border-top: 50px solid transparent;

border-right: 100px solid red;

border-bottom: 50px solid transparent;

}

2.4 Triangle Right

#triangle-right {

width: 0;

height: 0;

border-top: 50px solid transparent;

border-left: 100px solid red;

border-bottom: 50px solid transparent;

}

2.5 Triangle Top Left

#triangle-topleft {

width: 0;

height: 0;

border-top: 100px solid red;

border-right: 100px solid transparent;

}

2.6 Triangle Top Right

#triangle-topright {

width: 0;

height: 0;

border-top: 100px solid red;

border-left: 100px solid transparent;

}

2.7 Triangle Bottom Left

#triangle-bottomleft {

width: 0;

height: 0;

border-bottom: 100px solid red;

border-right: 100px solid transparent;

}

2.8 Triangle Bottom Right

#triangle-bottomright {

width: 0;

height: 0;

border-bottom: 100px solid red;

border-left: 100px solid transparent;

}