Hi Kiran
Thanks for posting! Unfortunately it's not currently possible to directly type in the dimensions of floorplan shapes. They have to be manually dragged to the required size. However I agree that this would be a great addition to our Floorplan Tools! Would you mind adding your idea to Lucid’s product feedback space? Ideas shared here are monitored by our product team and considered when updating Lucid products.
Also you might find it easier to precisely size your walls if you change the scale of your floor plan. Please see our Floorplan Tools article for more information about this. Hope this helps!