Question

I need 18,19,& 20•ignore my writing

Answer 1

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

$SA=2B+PH$            

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

$B=3.5*7=24.5\ m^{2}$

Find the perimeter of the base P

$P=2*(3.5+7)=21\ m$

we have

$H=2.4\ m$

substitute

$SA=2(24.5)+(21)(2.4)=99.4\ m^{2}$ ----> exact value

Estimate the surface area

we have

$L=3.5=4\ m$ ----> round up

$W=7\ m$

$H=2.4=2\ m$ ----> round down

Estimate the area of the base B

$B=4*7=28\ m^{2}$

Estimate the perimeter of the base P

$P=2*(4+7)=22\ m$

substitute in the formula

$SA=2(28)+(22)(2)=56+44=100\ m^{2}$

Part 19) Estimate the volume of the prism

The volume of the prism is equal to

$V=BH$

we have

$B=3.5*7=24.5\ m^{2}$

$H=2.4\ m$

substitute

$V=(24.5)(2.4)=58.8\ m^{3}$ ----> exact value

Estimate the volume

we have

$L=3.5=4\ m$ ----> round up

$W=7\ m$

$H=2.4=2\ m$ ----> round down

Estimate the area of the base B

$B=4*7=28\ m^{2}$

substitute in the formula

$V=(28)(2)=56\ m^{3}$    

Part 20) The volume of the prism is equal to

$V=BH$

we have

$B=6*6.8=40.8\ cm^{2}$

$H=5.2\ cm$

substitute

$V=(40.8)(5.2)=212.16\ cm^{3}$ ----> exact value

Estimate the volume

we have

$L=6\ cm$

$W=6.8=7\ cm$ ----> round up

$H=5.2=5\ cm$ ----> round down

Estimate the area of the base B

$B=6*7=42\ cm^{2}$

substitute in the formula

$V=(42)(5)=210\ cm^{3}$