( ( A meter ) ( ( is ( a ( measuring instrument ) ) ) . ) )
(ROOT (S (NP (DT A) (NN meter)) (VP (VBZ is) (NP (DT a) (NN measuring) (NN instrument))) (. .)))
A meter is a measuring instrument.
(ROOT (S (NP (NP (NNP Instruments)) (SBAR (WHNP (WDT that)) (S (VP (VB measure) (NP (NP (DT the) (NN angle)) (PP (IN of) (NP (NP (DT the) (NN slope)) (PP (IN of) (NP (DT a) (NN volcano)))))))))) (VP (VBP are) (VP (VBN called) (NP (NN tilt) (NNS meters)))) (. .)))