50 POINTS I NEED ALL OF THESE PRECALC

Find the perimeter of the triangle with vertices  d(3, 4),  e(8, 7), and  f(5, 9). do not round before calculating the perimeter. after calculating the perimeter, round your answer to the nearest tenth.  

The perimeter of a rectangular lot of land is 436 ft. this includes an easement of x feet of uniform width inside the lot on which no building can be done. if the buildable area is 122 ft by 60 ft, determine the width of the easement. select one: a. 9 feet b. 18 feet c. 4.5 feet d. 7 feet

Someone which statements are true? check all that apply.