Answer:
Part 18) Option D 100 square meters
Part 19) Option A 60 cubic meters
Part 19) Option C. 212 cubic centimeters
Step-by-step explanation:
Part 18) Estimate the surface area of the prism
we know that
The surface area of the prism is equal to
[tex]SA=2B+PH[/tex]
where
B is the area of the base
P is the perimeter of the base
H is the height of the prism
Find the area of the base B
[tex]B=3.5*7=24.5\ m^{2}[/tex]
Find the perimeter of the base P
[tex]P=2*(3.5+7)=21\ m[/tex]
we have
[tex]H=2.4\ m[/tex]
substitute
[tex]SA=2(24.5)+(21)(2.4)=99.4\ m^{2}[/tex] ----> exact value
Estimate the surface area
we have
[tex]L=3.5=4\ m[/tex] ----> round up
[tex]W=7\ m[/tex]
[tex]H=2.4=2\ m[/tex] ----> round down
Estimate the area of the base B
[tex]B=4*7=28\ m^{2}[/tex]
Estimate the perimeter of the base P
[tex]P=2*(4+7)=22\ m[/tex]
substitute in the formula
[tex]SA=2(28)+(22)(2)=56+44=100\ m^{2}[/tex]
Part 19) Estimate the volume of the prism
The volume of the prism is equal to
[tex]V=BH[/tex]
we have
[tex]B=3.5*7=24.5\ m^{2}[/tex]
[tex]H=2.4\ m[/tex]
substitute
[tex]V=(24.5)(2.4)=58.8\ m^{3}[/tex] ----> exact value
Estimate the volume
we have
[tex]L=3.5=4\ m[/tex] ----> round up
[tex]W=7\ m[/tex]
[tex]H=2.4=2\ m[/tex] ----> round down
Estimate the area of the base B
[tex]B=4*7=28\ m^{2}[/tex]
substitute in the formula
[tex]V=(28)(2)=56\ m^{3}[/tex]
Part 20) The volume of the prism is equal to
[tex]V=BH[/tex]
we have
[tex]B=6*6.8=40.8\ cm^{2}[/tex]
[tex]H=5.2\ cm[/tex]
substitute
[tex]V=(40.8)(5.2)=212.16\ cm^{3}[/tex] ----> exact value
Estimate the volume
we have
[tex]L=6\ cm[/tex]
[tex]W=6.8=7\ cm[/tex] ----> round up
[tex]H=5.2=5\ cm[/tex] ----> round down
Estimate the area of the base B
[tex]B=6*7=42\ cm^{2}[/tex]
substitute in the formula
[tex]V=(42)(5)=210\ cm^{3}[/tex]
