Perfect Solution for this question i finally found
just keep
.header, .footer{height:20%;}
.content{min-height:80%;}
!DOCTYPE html>
<html>
<head>
<style>
html,body{height:100%;}
.wrapper{position:relative; min-height:100%;}
.header{height:20%; left:0;top:0; background-color:red;}
.content{background-color:blue;min-height:80%;}
.footer{position:absolute;left:0;bottom:0; background-color:yellow;height:20%;; width:100%;}
</style>
</head>
<body>
<div class="wrapper">
<div class="header">
This is header
</div>
<div class="content">
This content <br>
</div>
<div class="footer">
this is footer
</div>
</div>
</body>
</html>