Find the surface area

Given that de, df, and ef are midsegments of △abc, and de=3.2 feet, ef=4 feet, and df=2.4 feet, the perimeter of △abc is .

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?

In the diagram, be and ad pass throughthe center of circle o, and the area ofsector aoc is 47.45 square units. what isthe area of sector boc? use the value =3.14, and round your answer to two decimalplaces.22.33 square units25.12 square units