css+div 绘制多边形

/*1.正方形*/

<div id="square"></div>

#square {
    width: 100px;
    height: 100px;
    background: red;
}

/*2.长方形*/

<div id="rectangle"></div>

#rectangle {
    width: 200px;
    height: 100px;
    background: red;
}

/*3.左上三角*/

<div id="triangle-topleft"></div>

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

/*4.右上三角*/

<div id="triangle-topright"></div>

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

/*5.左下三角*/

<div id="triangle-bottomleft"></div>

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

/*6.右下三角*/

<div id="triangle-bottomright"></div>

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

/*7.平行四边形*/

<div id="parallelogram"></div>

#parallelogram {
    width: 150px;
    height: 100px;
    -webkit-transform: skew(20deg);
    -moz-transform: skew(20deg);
    -o-transform: skew(20deg);
    background: red;
}

/*8.梯形*/

<div id="trapezoid"></div>

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

/*9.六角星*/

<div id="star-six"></div>

#star-six {
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-bottom: 100px solid red;
    position: relative;
}

#star-six:after {
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-top: 100px solid red;
    position: absolute;
    content: "";
    top: 30px;
    left: -50px;
}

/*10.五角星*/

<div id="star-five"></div>

#star-five {
    margin: 50px 0;
    position: relative;
    display: block;
    color: red;
    width: 0px;
    height: 0px;
    border-right: 100px solid transparent;
    border-bottom: 70px solid red;
    border-left: 100px solid transparent;
    -moz-transform: rotate(35deg);
    -webkit-transform: rotate(35deg);
    -ms-transform: rotate(35deg);
    -o-transform: rotate(35deg);
}

#star-five:before {
    border-bottom: 80px solid red;
    border-left: 30px solid transparent;
    border-right: 30px solid transparent;
    position: absolute;
    height: 0;
    width: 0;
    top: -45px;
    left: -65px;
    display: block;
    content: '';
    -webkit-transform: rotate(-35deg);
    -moz-transform: rotate(-35deg);
    -ms-transform: rotate(-35deg);
    -o-transform: rotate(-35deg);
}
#star-five:after {
    position: absolute;
    display: block;
    color: red;
    top: 3px;
    left: -105px;
    width: 0px;
    height: 0px;
    border-right: 100px solid transparent;
    border-bottom: 70px solid red;
    border-left: 100px solid transparent;
    -webkit-transform: rotate(-70deg);
    -moz-transform: rotate(-70deg);
    -ms-transform: rotate(-70deg);
    -o-transform: rotate(-70deg);
    content: '';
}

/*11.五边形*/

<div id="pentagon"></div>

#pentagon {
    position: relative;
    width: 54px;
    border-width: 50px 18px 0;
    border-style: solid;
    border-color: red transparent;
}

#pentagon:before {
    content: "";
    position: absolute;
    height: 0;
    width: 0;
    top: -85px;
    left: -18px;
    border-width: 0 45px 35px;
    border-style: solid;
    border-color: transparent transparent red;
}

/*12.六边形*/

<div id="hexagon"></div>

#hexagon {
    width: 100px;
    height: 55px;
    background: red;
    position: relative;
}

#hexagon:before {
    content: "";
    position: absolute;
    top: -25px;
    left: 0;
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-bottom: 25px solid red;
}

#hexagon:after {
    content: "";
    position: absolute;
    bottom: -25px;
    left: 0;
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-top: 25px solid red;
}

/*13.桃心*/

<div id="heart"></div>

#heart {
    position: relative;
    width: 100px;
    height: 90px;
}

#heart:before, #heart:after {
    position: absolute;
    content: "";
    left: 50px;
    top: 0;
    width: 50px;
    height: 80px;
    background: red;
    -moz-border-radius: 50px 50px 0 0;
    border-radius: 50px 50px 0 0;
    -webkit-transform: rotate(-45deg);
    -moz-transform: rotate(-45deg);
    -ms-transform: rotate(-45deg);
    -o-transform: rotate(-45deg);
    transform: rotate(-45deg);
    -webkit-transform-origin: 0 100%;
    -moz-transform-origin: 0 100%;
    -ms-transform-origin: 0 100%;
    -o-transform-origin: 0 100%;
    transform-origin: 0 100%;
}
#heart:after {
    left: 0;
    -webkit-transform: rotate(45deg);
    -moz-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    -o-transform: rotate(45deg);
    transform: rotate(45deg);
    -webkit-transform-origin: 100% 100%;
    -moz-transform-origin: 100% 100%;
    -ms-transform-origin: 100% 100%;
    -o-transform-origin: 100% 100%;
    transform-origin: 100% 100%;
}

/*14。无限大符号*/

<div id="infinity"></div>

#infinity {
    position: relative;
    width: 212px;
    height: 100px;
}

#infinity:before, #infinity:after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 60px;
    height: 60px;
    border: 20px solid red;
    -moz-border-radius: 50px 50px 0 50px;
    border-radius: 50px 50px 0 50px;
    -webkit-transform: rotate(-45deg);
    -moz-transform: rotate(-45deg);
    -ms-transform: rotate(-45deg);
    -o-transform: rotate(-45deg);
    transform: rotate(-45deg);
}
#infinity:after {
    left: auto;
    right: 0;
    -moz-border-radius: 50px 50px 50px 0;
    border-radius: 50px 50px 50px 0;
    -webkit-transform: rotate(45deg);
    -moz-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    -o-transform: rotate(45deg);
    transform: rotate(45deg);
}

/*15.蛋*/

<div id="egg"></div>

#egg {
    display: block;
    width: 126px;
    height: 180px;
     padding: 0px; color: rgb(0, 128, 0); font-weight: bold;">red;
    -webkit-border-radius: 63px 63px 63px 63px / 108px 108px 72px 72px;
    border-radius: 50% 50% 50% 50%  / 60% 60% 40% 40%;
}

/*16.提示对话框*/

<div id="talkbubble"></div>

#talkbubble {
    width: 120px;
    height: 80px;
    background: red;
    position: relative;
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
    border-radius: 10px;
}

#talkbubble:before {
    content: "";
    position: absolute;
    right: 100%;
    top: 26px;
    width: 0;
    height: 0;
    border-top: 13px solid transparent;
    border-right: 26px solid red;
    border-bottom: 13px solid transparent;
}

/*17.十二角星*/

<div id="burst-12"></div>

#burst-12 {
    background: red;
    width: 80px;
    height: 80px;
    position: relative;
    text-align: center;
    -webkit-transform: rotate(20deg);
    -moz-transform: rotate(20deg);
    -ms-transform: rotate(20deg);
    -o-transform: rotate(20deg);
    transform: rotate(20deg);
}

#burst-12:before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    height: 80px;
    width: 80px;
    background: red;
    -webkit-transform: rotate(120deg);
    -moz-transform: rotate(120deg);
    -ms-transform: rotate(120deg);
    -o-transform: rotate(120deg);
    transform: rotate(120deg);
}
#burst-12:after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    height: 80px;
    width: 80px;
    background: red;
    -webkit-transform: rotate(150deg);
    -moz-transform: rotate(150deg);
    -ms-transform: rotate(150deg);
    -o-transform: rotate(150deg);
    transform: rotate(150deg);
}

/*18.八角星*/

<div id="burst-8"></div>

#burst-8 {
    background: red;
    width: 80px;
    height: 80px;
    position: relative;
    text-align: center;
    -webkit-transform: rotate(20deg);
    -moz-transform: rotate(20deg);
    -ms-transform: rotate(20deg);
    -o-transform: rotate(20deg);
    transform: rotate(20deg);
}
#burst-8:before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    height: 80px;
    width: 80px;
    background: red;
    -webkit-transform: rotate(135deg);
    -moz-transform: rotate(135deg);
    -ms-transform: rotate(135deg);
    -o-transform: rotate(135deg);
    transform: rotate(135deg);
}

/*19.钻石*/

<div id="cut-diamond"></div>

#cut-diamond {
    border-style: solid;
    border-color: transparent transparent red transparent;
    border-width: 0 25px 25px 25px;
    height: 0;
    width: 50px;
    position: relative;
}

#cut-diamond:after {
    content: "";
    position: absolute;
    top: 25px;
    left: -25px;
    width: 0;
    height: 0;
    border-style: solid;
    border-color: red transparent transparent transparent;
    border-width: 70px 50px 0 50px;
}

/*20.阴阳鱼*/

<div id="yin-yang"></div>

#yin-yang {
    width: 96px;
    height: 48px;
    background: #eee;
    border-color: red;
    border-style: solid;
    border-width: 2px 2px 50px 2px;
    border-radius: 100%;
    position: relative;
}

#yin-yang:before {
    content: "";
    position: absolute;
    top: 50%;
    left: 0;
    background: #eee;
    border: 18px solid red;
    border-radius: 100%;
    width: 12px;
    height: 12px;
}

#yin-yang:after {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    background: red;
    border: 18px solid #eee;
    border-radius: 100%;
    width: 12px;
    height: 12px;
}

/*21八边形*/

<div id="bagua"></div>
#bagua {
    width: 100px;
    height: 240px;
    position: relative;
    background: red;
}

#bagua:after, #bagua:before {
    position: absolute;
    top: 0;
    content: "";
    width: 0;
    height: 100px;
    border-top: 70px solid transparent;
    border-bottom: 70px solid transparent;
}

#bagua:after {
    left: 100%;
    border-left: 70px solid red;
}

#bagua:before {
    right: 100%;
    border-right: 70px solid red;
}