Question

PLZ HELP will medal.........What is the surface area of this rectangular prism?

Answer 1

418cm2
520cm2
836cm2
209cm2

Answer 2

do you know how to find surface area?

Answer 3

nope

Answer 4

what about area?

Answer 5

yes

Answer 6

base times hieght

Answer 7

yep! Excellent :).
So when they ask you for surface area it means :
The TOTAL area of the surface of a 3-Dimensional object.

Answer 8

so 8 times 5?

Answer 9

or 13 times 5

Answer 10

Firstly, how many sides does the rectangular prism have?

Answer 11

6

Answer 12

Yes!
So that means you have to find the area of the 6 sides and then add them all together to get the TOTAL area

Answer 13

do you understand?

Answer 14

i got 520 when i did 5*8*13.do i times that by 2?

Answer 15

Not quite.
If you do 5*8*13 that will give you volume and not surface area.
You have to find the area of each side and add them together.

Answer 16

13*13.....5*5....and 8*8 ?is that what i do?

Answer 17

So let's begin with the smallest sides!
How do you find the area of the smallest rectangle?

Answer 18

you do 5*5?

Answer 19

area is base times height, remember?
So the smallest rectangle has a base of 8 and a height of 5 right?

Answer 20

What would the area of that rectangle be?

Answer 21

40

Answer 22

yep! So 40 is just for that one small rectangle.
But remember, there is another small rectangle which is the same size.
So what would you do?

Answer 23

do 40 *2?

Answer 24

which is 80

Answer 25

Exactly!
So we know that the total surface area of the smallest rectangles = 80
Now, we do the same for the other rectangles.

Answer 26

13*5=65*2=130

Answer 27

yep :)
You're understanding this really well.
Okay and now you have one final set of rectangles to go.

Answer 28

is it 8 x 13?

Answer 29

yeah but there are two rectangles that size! (Top and bottom)

Answer 30

8*13=104......104*2=208

Answer 31

Yes!
So now the TOTAL surface area would be?

Answer 32

418

Answer 33

YAY :D!
Great work .

Answer 34

thank you so much. :D

Answer 35

No worries :) hehe

Answer 36

would this formula be the same for a triangular prism?

Answer 37

yep :)
Just remember that for surface area of any prism, you just add all the areas together.
So in a triangular prism, you find the area of the two triangles and then the other three rectangle sides.
Add it all up, and you should get your answer!

Answer 38

ok thanks:)

Answer 39

you're welcome !!

Answer 40

let me know if you need help i any thing.sorry it took so long im just bad with surface area.

Answer 41

Sure will and the same goes for you!
haha don't worry, i was horrible at it also.
Just practice :)

Answer 42

surface area=2(l*b+b*h+h*l)

Answer 43

LOL that was so much simpler... xD
But yes, @lcnettech you can also just use the equation provided by @surjithayer .
Surface area = 2(l*b + b*h + h*l)