( ( ( The distance ) ( from ( ( the ( reflecting surface ) ) ( to ( the ( focal point ) ) ) ) ) ) ( ( is ( termed ( ( the ( mirror 's ) ) ( focal length ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN distance)) (PP (IN from) (NP (NP (DT the) (JJ reflecting) (NN surface)) (PP (TO to) (NP (DT the) (JJ focal) (NN point)))))) (VP (VBZ is) (VP (VBN termed) (NP (NP (DT the) (NN mirror) (POS 's)) (JJ focal) (NN length)))) (. .)))
The distance from the reflecting surface to the focal point is termed the mirror's focal length .
(ROOT (S (NP (NNP Distance)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (DT the) (NN length)) (PP (IN of) (NP (NP (DT the) (NN route)) (PP (IN between) (NP (CD two) (NNS points))))))))) (. .)))