PLS HELP. I NEED URGENT HELP AND SHOW WORK

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 .

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed

Which zero pair could be added to the function f(x) = x2 + 12x + 6 so that the function can be written in vertex form? o 3, -3o 6,629,-936, 36