Let G be an abelian group and let g,h in G, assume that |g|,|h| (the order of g and h) are both finite,with hcf(|g|,|h|)=1.then Prove that |g+h|=|g|*|h|

i dont know how to relate the order of g,h to the order of |g+h| could somone give me any hints ??