( This ( ( is ( ( an exploration ) ( of ( ( ( the ( third dimension ) ) , ) ( that ( of ( ( volumes and ) shapes ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ is) (NP (NP (DT an) (NN exploration)) (PP (IN of) (NP (NP (DT the) (JJ third) (NN dimension)) (, ,) (NP (NP (DT that)) (PP (IN of) (NP (NNS volumes) (CC and) (NNS shapes)))))))) (. .)))
This is an exploration of the third dimension, that of volumes and shapes.
(ROOT (S (NP (NP (DT The) (NN volume)) (PP (IN of) (NP (DT a) (ADJP (ADVP (RB regularly)) (JJ shaped)) (JJ solid)))) (VP (MD can) (VP (VB be) (VP (VBN calculated) (PP (IN from) (NP (PRP$ its) (NNS dimensions)))))) (. .)))