.block1{
    background-color: blue;
    float: left;
    height: 200px;
    width: 200px;
    margin: 10px;

}
.block2{
    margin-left: 20px;
    height: 200px;
    width: 150px;
    background-color: crimson;
    float: right;
}
.block3{
    margin-left: 20px;
    height: 100px;
    width: 150px;
    background-color: yellowgreen;
    float: ri;
}