Angela owns a set of 6-inch tall glasses. Each glass has a diameter of 3 inches. Angela has three people over for dinner. Each guest will be served a full glass of milk. How much milk will Angela need?

Dimensions of the glasses: Diameter, d = 3 in; depth, h = 6 in

Volume of 1 glass = (πd^2/4) * h = (π*3^2/4) * 6 = 42.41 in^3

Each of the three guests will be served a glass full of milk.

Volume of milk required = 3*volume of 1 glass = 3*42.41 = 127.23 in^3

But,

1 in^3 = 0.0163871 liters

Therefore,

127.23 in^3 = 127.23*0.0163871 ≈ 2.09 liters will be required.