About 19.6 pounds of CO2 are produced from burning a (US) gallon of gasoline.
Source: www.eia.gov/tools/faqs/faq.php?id=307&t=11
So the mass of CO2 produced by burning 1 tank of gasoline is
19.6*13.2=258.7 pounds.
assume the square side = x, then its circumference = 4x
so the circle circumference would be 89 - 4x which equals 2pi r
so x = 1/4 (89 - 2pi r)
now A(r) = x^2 + pi r^2
= [1/4 (89 - 2pi r)]^2 + pi r^2
diff. w.r.to r u get:
dA/dr = 1/8 (89-2 pi r)(-2 pi) + 2 pi r = 0
2pi r - pi/4 (89-2 pi r) = 0
2r - (89 - 2 pi r)/4 = 0
2r + pi r /2 = 89/4
mult. the eqn by 4 and solve for r u get:
r = 89 / (8 + 2pi) cm
and the circle circumference = 2 pi r = 2 pi 89 / (8 + 2pi)
= 178 pi / (8 + 2pi) = 89 pi /(4 + pi) cm
hope this helps
15 and 10 with a guess do not write this
