( ( ( ( ( Similarly ( we ( can ( prove ( that ( ( each ( of ( ( the ( remaining triangles ) ) ( of ( which ( ( ( the sides ) ( of ( the ( square EFGH ) ) ) ) ( are ( ( ( the bases ) and ) ( ( the points ) ( ( ( L and ) M ) ( are ( the vertices ) ) ) ) ) ) ) ) ) ) ) ) ( , ( is equilateral ) ) ) ) ) ) ) ) , ) therefore ) ( ( an octahedron ) ( has ( been ( constructed ( which ( is ( contained ( by ( eight ( equilateral triangles ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (ADVP (RB Similarly)) (NP (PRP we)) (VP (MD can) (VP (VB prove) (SBAR (IN that) (S (NP (NP (DT each)) (PP (IN of) (NP (NP (DT the) (VBG remaining) (NNS triangles)) (PP (IN of) (SBAR (WHNP (WDT which)) (S (NP (NP (DT the) (NNS sides)) (PP (IN of) (NP (DT the) (JJ square) (NNS EFGH)))) (VP (VBP are) (NP (NP (DT the) (NNS bases)) (CC and) (NP (NP (DT the) (NNS points)) (SBAR (S (NP (NNP L) (CC and) (NNP M)) (VP (VBP are) (NP (DT the) (NNS vertices)))))))))))))) (, ,) (VP (VBZ is) (ADJP (JJ equilateral)))))))) (, ,) (ADVP (RB therefore)) (S (NP (DT an) (NN octahedron)) (VP (VBZ has) (VP (VBN been) (VP (VBN constructed) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (VP (VBN contained) (PP (IN by) (NP (CD eight) (JJ equilateral) (NNS triangles))))))))))) (. .)))
Similarly we can prove that each of the remaining triangles of which the sides of the square EFGH are the bases and the points L and M are the vertices, is equilateral, therefore an octahedron has been constructed which is contained by eight equilateral triangles.
(ROOT (S (NP (NP (DT The) (CD eight) (NNS sides)) (PP (IN of) (NP (DT an) (NN octahedra)))) (VP (VBP are) (PP (IN in) (NP (NP (DT the) (NN shape)) (PP (IN of) (NP (DT a) (NNS triangles)))))) (. .)))