30 coins 1/6 of them pennies 1/5 of them nickels 1/3 of them dimes

The polygon tool to draw a rectangle with a length of 5 units and a height of 3 units. one of the sides of the rectangle falls on line ab , and the rectangle has a vertex of a. each segment on the grid represents 1 unit.

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 .

Anna is constructing a line segment that is congruent to another segment ab. for the construction, which tool should be used to mesure segment ab