Please help me figure out how my professor solved this problem

Problem (2) you are given a roll of wire whose resistivity is po := 0.55 . . cm. You use a micrometer and find the the diameter of the wire is Divine :=3.000 . mm . (a) find the cross sectional area of the wire. (b) Using the result from (a) determine the length of the wire needed to create a resistor of Ro := 1.00. 0. D, 2 (a) wire Awire = 1 . = (7.069 - 10-") m 2 (6 ) A wire Lans:= Ro. (1.285 - 10-3) m Po