How to set the height of the block in which the bootstrap carousel is 4?

Question

css

Good evening!
How can I set the height of the block s1 so that the carousel has a fixed height?
I tried, but the inscriptions on the result are simply not visible!

.carousel-inner{
    height: 750px;
}

<section class="carousel" id="carousel">
    <div class="s1">
      <div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel">
        <ol class="carousel-indicators">
          <li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
          <li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
          <li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
        </ol>
        <div class="carousel-inner">
          <div class="carousel-item active">
            <img class="d-block w-100" src="img/carousel_s1.jpg" alt="First slide">
            <div class="carousel-caption d-none d-md-block">
                <h5>Lorem ipsum.</h5>
                <p>Lorem ipsum dolor.</p>
            </div>
          </div>
          <div class="carousel-item">
            <img class="d-block w-100" src="img/carousel_s2.jpg" alt="Second slide">
            <div class="carousel-caption d-none d-md-block">
                <h1>Lorem ipsum.</h1>
                <p>Lorem ipsum dolor.</p>
            </div>
          </div>
          <div class="carousel-item">
            <img class="d-block w-100" src="img/carousel_s3.jpg" alt="Third slide">
            <div class="carousel-caption d-none d-md-block">
                <h5>Lorem ipsum.</h5>
                <p>Lorem ipsum dolor.</p>
            </div>
          </div>
        </div>
        <a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
          <span class="carousel-control-prev-icon" aria-hidden="true"></span>
          <span class="sr-only">Previous</span>
        </a>
        <a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
          <span class="carousel-control-next-icon" aria-hidden="true"></span>
          <span class="sr-only">Next</span>
        </a>
      </div>
    </div>
    </section>

Answer 1

In the current layout, you need to add the img-fluid class to images
and set the height in CSS

.carousel-item img {
    height: 750px;
}