Heather is building a ladder for her treehouse. she will need 13 feet of lumber for each stilt and 2 feet of lumber for each rung on the ladder. how many feet of lumber does she need for a ladder with 2 stilts and 12 rungs? a. 29 feet because 2+13+12+2=29 b. 50 feet because 2(13)+12(2)=50 c. 160 feet because 13(12)+2(2)=160 d. 210 feet because (2+13)(12+2)=210