Is the relation a function? why or why not

Aphrase is shown read the phrase and give me the answer

Apack of gum would be considered a(n) necessity luxury item small ticket item unaccountable expense

The perimeter of ? cde is 55 cm. a rhombus dmfn is inscribed in this triangle so that vertices m, f, and n lie on the sides cd , ce , and de respectively. find cd and de if cf=8 cm and ef=12 cm. the answer is not cd=20 and de=15. i have tried that one, it does not work.