Question

I need help ASAP THANK YOU!!

Answer 1

a.

v= 819 cm3

sa= 542 cm2

b. surface area

c. volume

Explanation:

Volume of a rectangular prism: Length x width x height

Replacing with the values given:

V = 13 x 9 x 7 = 819 cm3

Surface area = S = 2 × (W × L + L × H + H × W)

S = 2 ( [9x13]+ [13 x7] +[7x9]) = 2 ( 117+91+63)= 542 cm2

b . Surface area, because we only have to paint the exterior of the brick.

c. Volume, because is the amount of concrete that the brick has.

Answer 2

A. Volume: 819, Surface Area: 598

B. Surface area

C. Volume

Explanation:

Sorry I'm late, but here I go.

The volume of a rectangular prism is
`lwh` or
`bh`. (l being length, w being width, and h being height.)

So if we multiply the 3 values of 13, 9, and 7, we get 819. This is the volume.

To find the surface area, we can take note that 4 sides are the exact same, and the remaining two are the same. Let's find the area of the top/bottom of the prism.

`13\cdot9=117`

Since there are two, bottom and top:

`117\cdot2 = 234`.

Now, there are the remaining 4 sides. Let's find the area of one then multiply it by 4.

`13\cdot7=91\\91\cdot4=364`

Adding 364 and 234 gets up 598, so this is the surface area.

If we are painting something, the surface area is being painted, as we can't paint inside the box. However if we fill up the box with something (concrete in this case), it will be the volume.

Hope this helped!