Cant fail this math question? ? , show

What is the radius of the cone in the diagram? round your answer to the nearest whole number

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.

5,678.321 what place value is the 1 in