problem adding images to custom page.

trying to create a css slide show for the header.
my images are not showing up. is there a wordpress tag for this? I don’t recall one.
the code i am using would normally bring in the image for regular pages . Usually for wp I use the

background-image: url (' ');

but for a slide show i need to create a div, i also tried to see if it may be due to being up or down a folder but that did not help either

<div id="hdrSlide">
<div>
<img src="contentImages/hangarScene.png" alt="aerospace industry">
<img src="contentImages/oilRef01.png" alt="oil engineering">
<img src="./contentImages/oilRef02.png" alt="oil engineering">
<img src="../contentImages/oilRef03.png" alt="oil engineering">
</div>
</div>

thank you
d