More info is needed. If you were able to provide the radius of the base of the tea glasses as well as the height (8 inches), then it'd be possible to calculate the volume of one such glass. Are these short and fat tea glasses? or tall and slim tea glasses? My point: We don't know. Try to supply the missing info.
There are 10 such 8-inch tea glasses. Of course you could multiply 10 and 8 to get 80 inches, but 80 inches is NOT a suitable measure of the volume of a liquid.