Explanation:
i hope i didnt answer too late i see that ot says 7 min remaining but oh well
the answer
equation: (7x-13)+(x+29)+(3x + 5) = 180 (the reason why i put = to 180 is because every triangle adds up to 180 degrees)
first of all add the numbers: 29-13+5 = 21--- then add variables: 7x+3x+x= 11x
you get ur equation as: 11x + 21 = 180--- 180-21=11x---159=11x--- 159/11=14 9/20
x = 14 9/20 permiter = 88.15 + 43.45 + 48.35 = 179.95
really hope this helps :) good luck