I leave the following code maybe someone could give me some clues to solve: the image shows the error.
h1{margin:0}
.div-cut.top {
top: 0;
border-top: 250px solid #fff;
border-right: 100vw solid red;
}
.div-cut {
position: absolute;
z-index: 1;
left: 0;
width: 100%;
height: 0;
}
.absolut{position:absolute;}
.fix{position:fixed}
.EstilosParaFondo{
z-index:10;
top:0; top:0; left:0; right:0;
margin:auto;
background-image:url('images/imagenOK.jpg');
background-size:cover;
background-repeat:no-repeat;
height: 450px;
}
<div style="background:white; height:80vh; width:100%">
<h1>Hello, world 1</h1>
</div>
<div id="div2" style="position:relative; background-color:#FF4D4D;">
<div id="triangle" class=" div-cut top">jofret</div>
<div>
<div style="height:100vh">
<h1>Hello, world 2</h1>
holaaaaaaaa
</div>
<div style="height:100vh">
<h1>Hello, world 3</h1>
holaaaaaaaa
</div>
<div style="height:100vh">
<h1>Hello, world 4</h1>
holaaaaaaaa
</div>
<div style="height:100vh">
<h1>Hello, world 5</h1>
holaaaaaaaa
</div>
<div style="height:100vh">
<h1>Hello, world 6</h1>
holaaaaaaaa
</div>
<div class="opera" style="height:100vh">
<h1>Hello, world 7</h1>
holaaaaaaaa
</div>
</div>
</div>