( ( Start ( with ( ( a ( triangle-shaped base ) ) ( of 15 ) ) ) ) ( ( ( tetrahedrons ( with 5 ) ) ( to ( ( each side ) ( of ( the triangle ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Start)) (PP (IN with) (NP (NP (DT a) (JJ triangle-shaped) (NN base)) (PP (IN of) (NP (CD 15)))))) (VP (VBZ tetrahedrons) (PP (IN with) (NP (CD 5))) (PP (TO to) (NP (NP (DT each) (NN side)) (PP (IN of) (NP (DT the) (NN triangle)))))) (. .)))
Start with a triangle-shaped base of 15 tetrahedrons with 5 to each side of the triangle.
(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)))))) (. .)))