Everyone is familiar with the standard straight bath but there is now a variation on this available designed specifically for use as a shower bath.
The shower end of the bath bulges outward to provide extra room for showering. This type of bath has a glass bath shower screen shaped to fit the curve. Some models have an extra screen that can be attached to give a complete shower cubicle effect. The standard curved screen usually pivots to enable access to the taps and to aid cleaning. Some shower baths have the taps mounted on the outside rim which makes reaching them easier but usually means that it is not possible to fit a second glass screen and can result in sprayed water from the shower escaping the shower area - especially if a power shower is used.
The dimensions for these baths can vary but they are usually a similar length to a standard bath - 1700mm. Make sure that the extra width required at the shower end does not encroach on other items in the bathroom such as the toilet or wash hand basin. We have a further section comparing shower cubicles and shower baths here