Make an image fit its container by setting the image height to the containers heights

Question

Say I have container.a and it has some height in pixels, say I have another container.b within container.a that is 80% of container.a, now say I want to fit an image that ha

Answer 1

Use this:

.image.a { height:100%; width:auto }

Answer 2

Give 100% width of image

 .image.a{width:100%;}