My tiny bathroom measures only 190cm x 155cm and comprises a shower cubicle,
a toilet and a basin.

Luxery! My bathroom is 192cm x 72cm!

The bath (170x70) must go along one long side, wasting 20x70;
The shower (80x80) would probably need to go in one of the
remaining two corners, wasting 80x5.

A shower **and** a bath? Put the show over the bath.

JGH