How to make each of columns get equal height in Bootstrap 4?

Question

Take a look this picture:

2nd column is at right, it looks the height isn't equal to the first column I need to figure out how 2nd column should get the same height as the first column.

My HTML:

<div class="row"">
  <div class="col-8">
    <div class="row">
      <div class="col-12 mb-2">
        <div class="imgcontainer">
          <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
          <div class="top-left">Top Left</div>
        </div>
      </div>
      <div class="col-12">
        <div class="imgcontainer">
          <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
          <div class="top-left">Top Left</div>
        </div>
      </div>
    </div>
  </div>
  <div class="col-4">
    <div class="row">
      <div class="col-12">
        <div class="imgcontainer">
          <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
          <div class="top-left">Top Left</div>
        </div>
      </div>
      <div class="col-12">
        <div class="imgcontainer">
          <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
          <div class="top-left">Top Left</div>
        </div>
      </div>
      <div class="col-12">
        <div class="imgcontainer">
          <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
          <div class="top-left">Top Left</div>
        </div>
      </div>
    </div>
  </div>
</div>

Answer 1

You can try something like this:

<div class="container">
  <div class="d-md-flex">
    <div class="flex flex-row flex-nowrap">
      <img src="https://i.imgur.com/exWWySt.png">
      <img src="https://i.imgur.com/exWWySt.png">
    </div>

    <div class="flex-column">
      <img src="https://i.imgur.com/exWWySt.png" height="300">
      <img src="https://i.imgur.com/exWWySt.png" height="300">
      <img src="https://i.imgur.com/exWWySt.png" height="300">
    </div>
  </div>
</div>

Codepen

Answer 2

Use the flexbox utils to make the right column display:flex, flex-direction: column...

<div class="container-fluid">
    <div class="row">
        <div class="col-8">
            <div class="row">
                <div class="col-12 mb-2">
                    <div class="imgcontainer">
                        <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
                        <div class="top-left">Top Left</div>
                    </div>
                </div>
                <div class="col-12">
                    <div class="imgcontainer">
                        <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
                        <div class="top-left">Top Left</div>
                    </div>
                </div>
            </div>
        </div>
        <div class="col-4 d-flex flex-column">
            <div class="row flex-fill justify-content-between">
                <div class="col-12">
                    <div class="imgcontainer">
                        <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
                        <div class="top-left">Top Left</div>
                    </div>
                </div>
                <div class="col-12">
                    <div class="imgcontainer">
                        <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
                        <div class="top-left">Top Left</div>
                    </div>
                </div>
                <div class="col-12 d-flex align-items-end">
                    <div class="imgcontainer">
                        <img src="https://loremflickr.com/1280/720" class="img-fluid" alt="Picture">
                        <div class="top-left">Top Left</div>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

https://www.codeply.com/go/hlHhjz3K1Q