A model rocket is launched from the top of a hill 10 meters above ground level. The rocket's initial speed is 10 meters per second. Its height h can be modeled by the equation h = 4.91° +10 +10, where t is the time in seconds

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.