Question

I need 18,19,& 20•ignore my writing

Answer 1

Part 18) Option D 100 square meters

Part 19) Option A 60 cubic meters

Part 19) Option C. 212 cubic centimeters

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)`