How could I make a trapezius div

Question

How could I make the effect of below picture with HTML, CSS using the the bootstrap framework?

I need two adjacent divs with trapezoid shape (or separated by a diagonal line). Both need to have a border.

Answer 1

You can do this by drawing a shape in CSS.

You can draw such a triangle in CSS by playing with different borders (top, right, bottom left) of an element that has zero width.

Example: https://css-tricks.com/snippets/css/css-triangle/

In the example below I use the pseudo element :after for this effect:

/* Apply styles to both DIVs */
.container > div {
  width: 50%;
  float:left;
  font-weight: bold;
  padding-left: 10px;
  /* include padding in the height/width */
  box-sizing: border-box;
  margin: 0;
}

.container {
/* One way to make the DIV height extend to full heihgt of `float:left` DIVs inside it. Not the only way */
  clear: both;
}

.container div:first-child {
  background: #66ff66;
  /* The triangle will be position:absolute, so it requires a `position:relative` parent */
  position: relative;
  /* We are drawing a full rectangle later, so we hide the rest of it */
  overflow: hidden;
}

.container div:last-child {
  background: #ff6666;
}

.container div:first-child:after {
  position: absolute;
  display: block;
  content: ' ';
  padding: inherit;
  box-sizing: border-box;

  /* Change below units (you can use px not just em) 
    to make the line  become at different angles */
  border-top: 1.3em solid transparent;
  border-bottom: 1.3em solid transparent;
  border-right: 1.3em solid #ff6666;

  right: 0;
  top: 0;
}

<div class="container">
 <div>div١</div>
 <div>div٢</div>
</div>

Update

But as you indicated in the comment, you wanted a different answer that uses div2 for the triangle, so here you are:

/* Apply styles to both DIVs */
.container > div {
  width: 50%;
  float:left;
  font-weight: bold;


  /* include padding in the height/width */
  box-sizing: border-box;
  margin: 0;
}

.container {
/* One way to make the DIV height extend to full heihgt of `float:left` DIVs inside it. Not the only way */
  clear: both;
}

.container div:first-child {
  background: #66ff66;
  padding-left: 10px;

}

.container div:last-child {
  background: #ff6666;
  position: relative;
  padding-left: 1.3em;
}

.container div:last-child:before {
  position: absolute;
  content: '';.
  width: 0;
  height: 0;

  box-sizing: border-box;

  /* Change below units (you can use px not just em) 
    to make the line  become at different angles */
  border-top: 1.3em solid #66ff66;
  border-bottom: 1.3em solid transparent;
  border-right: 1.3em solid transparent;

  top: 0;
  left: 0;
}

<div class="container">
 <div>div١</div>
 <div>div٢</div>
</div>

Update 2

The picture you showed in comments also included real borders. This requires changing the approach. The new approach still uses :before, but adds border to it, and rotates it 45 degrees.

The idea is based on an example from: https://kilianvalkhof.com/2017/design/sloped-edges-with-consistent-angle-in-css/

To imagine it:

Here's the code:

/* Apply styles to both DIVs */
.container > div {
  width: 50%;
  float:left;
  font-weight: bold;


  /* include padding in the height/width */
  box-sizing: border-box;
  margin: 0;
}

.container {
/* One way to make the DIV height extend to full heihgt of `float:left` DIVs inside it. Not the only way */
  clear: both;
}

.container div:first-child {
  background: #66ff66;
  padding-left: 10px;
  border: 1px solid;
  border-right: none;
}

/* 
  The following assumes diemnsions 1.3em * 1.3em
  Your real case can change the number
*/

.container div:last-child {
  background: #ff6666;
  position: relative;
  border: 1px solid;
  border-left: none;
  padding-left: calc(1.5 * 1.3em);
  overflow: hidden;
}

.container div:last-child:before {
  position: absolute;
  content: '';
  width: calc(2 * 1.3em);
  height: calc(2 * 1.3em);

  box-sizing: border-box;
  background: #66ff66;

  border: 1px solid ;
  transform:rotate(45deg);

  margin-top: -1.3em;
  margin-left: -1.3em;
  left: 0;
  top: 0;
}

<div class="container">
 <div>div١</div>
 <div>div٢</div>
</div>

Answer 2

just use border-right like following code snippet and see result :

.parent{
  width: 100%;
  display: flex;
  background-color: #01579b;
}

.div1 {
  width: 30%;
  border-bottom: 100px solid #000;
  border-right: 50px solid transparent;
}

.div2 {
  width: 70%;
  height: 100px;
}

<div class="parent">
  <div class="div1"></div>
  <div class="div2"></div>
</div>