The centripetal force F in newtons exerted on a passenger by a spinning amusement park ride and the number of seconds t the ride takes to complete one revolution are related by the following equation: t = √([1620π2]/F)

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.