.square, .circle {
    width: 100px;
    height: 100px;
    display: inline-block;
    float: right;
}
.circle {
    border-radius: 50%;
}
#blockRed {
    background-color: palevioletred;
}
#blockYellow {
    background-color: greenyellow;
}
#blockCloud {
    background-image: url(https://wallpapers.com/images/featured/minimalist-pattern-7mairbffr65txpfi.jpg)
}
#container {
    background-color: lightgoldenrodyellow;
    display: block;
    margin: 0 auto;
    height: 400px;
    width: 400px;
}