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# how to solve this challenge

How to solve this challenge: 4th challenge: Switch the order of the arguments. Be sure to specify the variable for each argument, or you'll wind up with a height and width of red and a 1px solid 10px border! (Needless to say, that would be invalid.) //answer for upto 3 challenges is @mixin square(\$size, \$color:black) { width: \$size; height: \$size; border: 1px solid \$color; }

.box { @include square(10px, red) }

index.html
```<!DOCTYPE html>
<html>
<title>Sass Basics - Code Challenge</title>
<body>
<div class="box"></div>
<div class="red"></div>
<div class="orange"></div>
<div class="yellow"></div>
<div class="green"></div>
</body>
</html>
```
style.scss
```/* Write your SCSS code below. */
@mixin square(\$size, \$color:black) {
width: \$size;
height: \$size;
border: 1px solid \$color;
}

.box {
@include square(red, 10px)
}
```

```@mixin square(\$size, \$color: black) {
width: \$size;
height: \$size;
border: 1px solid \$color;
}

.box {
@include square(\$color: red, \$size: 10px); // Just specify variables and give them arguments like this
}

@mixin rainbow(\$colors...) {
@each \$color in \$colors {
.#{\$color} {
background: \$color;
}
}
}

@include rainbow(red, orange, yellow, green);
```