Advanced Angled Mixin - https://fewerthanthree.com/tutorials/using-sass-mixin-to-create-anlgled-sections

advanced-angled-mixin.scss

@mixin angled( $background-color, $top: true, $bottom: true, $reversed: false, $height: '1.5deg' ) {
    position: relative;

    @if $top {
        &::before {
            display: block;
            position: absolute;
            top: 0;
            left: 0;
            content: '';
            height: 50%;
            width: 100%;
            background-color: $background-color;
            z-index: -1;
        }
    }

    @if $bottom {
        &::after {
            display: block;
            position: absolute;
            bottom: 0;
            left: 0;
            content: '';
            height: 50%;
            width: 100%;
            background-color: $background-color;
            z-index: -1;
        }
    }

    @if $reversed {
        &::before,
        &::after {
            transform: skewY( -#{$height} );
        }

        &::before {
            top: 0;
            transform-origin: top left;
        }

        &::after {
            bottom: 0;
            transform-origin: bottom right; 
        }
    } @else {
        &::before,
        &::after {
            transform: skewY( #{$height} );
        }

        &::before {
            transform-origin: top right;
        }

        &::after {
            transform-origin: bottom left;
        }
    }
}