13.
find the areas of each individual recatngle and add them
rectangles of same color have same area
area=legnth times width
green=9 times 7.2=64.8
blue=7.2 times 6=43.2
yellow=9 times 6=54
double all of them and dd them since they have 2 rectangles of each color
64*2+63.2*2+54*2=324 m^2
14.
the formula can be condensed into
SA=2(LW+LH+WH)
SA=surface aera
LW=legnth times width
LH=legnth times height
WH=width times height
L=7
W=5
H=3
SA=2(7*5+7*3+5*3)
SA=2(35+21+15)
SA=2(71)
SA=142 ft^2
15. SA=2(LW+LH+WH)
L=12.7
W=8.1
H=4.3
SA=2(12.7*8.1+12.7*4.3+8.1*4.3)
SA=2(102.87+54.61+34.83)
SA=2(192.31)
SA=384.62 cm^2
16. SA=2(LW+LH+WH)
L=38
W=19
H=19
SA=2(38*19+38*19+19*19)
SA=2(722+722+361)
SA=2(1805)
SA=3610 in^2
17. SA=2(LW+LH+WH)
L=7.5
W=5.5
H=9
a.
SA=2(7.5*5.5+7.5*9+5.5*9)
SA=2(41.25+67.5+49.5)
SA=2(158.25)
SA=316.5 in^2
b. 7.5 times 2=15
newL=15
SA=2(15*5.5+15*9+5.5*9)
SA=2(82.5+135+49.5)
SA=2(267)
SA=534 in^2
c.
newL=7.5/2=3.75
SA=2(3.75*5.5+3.75*9+5.5*9)
SA=2(20.625+33.75+49.5)
SA=2(108.875)
SA=207.75 in^2
PLEASE READ THROUGH ALL STEPS TO GET ANSWERS