*A right circular, conical vessel of altitude 21 cm and base radius 11 cm is kept with its vertex downwards. If 2 litres of water is poured into it, how high above the vertex will the level of the water be?*

I think I need to convert the 2 L to 2000 cc's, and use similar similar triangles to find the height of the water cone. Does that sound right? Thanks!

p.s. I'm supposed to use 22/7 for , which makes the answer come out very "neat". If the answer is supposed to be 19 and 1/11 cm, then I've done it right.