+0

# another question aha ha

0
43
7
+23

Find the surface area of the composite figure.

May 2, 2020

#1
+299
+3

First, let's find the surface area of the thicc green rectangular prism.

One side is $$4 \cdot 10 = 40 \text{ cm}^2$$, and since there's 2, that makes $$80\text{ cm}^2$$.

Another side is $$4 \cdot 5 = 20 \text{ cm}^2$$, and again multiplied by 2 is $$40 \text{ cm}^2$$.

The final side is $$10 \cdot 5 = 50 \text{ cm}^2$$, and 2x that is $$100 \text{ cm}^2$$.

Let's add those all up, and we get $$80+40+100 = 220 \text{ cm}^2$$ :D

But of course, this doesn't include the area that has been sealed off by the pink long rectangle. That area is $$2 \cdot 2 = 4 \text{ cm}^2$$, so the total surface area of the green rectangular prism is $$220 - 4 = 216 \text{ cm}^2$$ :D

Now for the pink long rectangle.

One side is $$6 \cdot 2 = 12 \text{ cm}^2$$, and there are actually 4 of those, which makes $$12 \cdot 4 = 48 \text{ cm}^2$$ :D

Now solve the rest!

May 2, 2020
#2
+111360
+1

THX, CentsLord     !!!!

CPhill  May 2, 2020
#3
+23
+1

It still says the answer isn't correct

flxm3s  May 3, 2020
#5
+299
+2

That is because I didn't post a full answer on mine, I left the rest up to you :D

CentsLord  May 3, 2020
#6
+23
0

well, thank you for the help! :)

flxm3s  May 3, 2020
#4
+111360
+2

The easiest way to do this  is to find the surface area of each figure and subtract  twice the area  where the figures touch = 2 (2x 2)  =  8cm^2

Surface area of top figure  =  4 (6 *2)  + 2 (2*2)  =   56 cm^2

Surface area of bottom figure  =   2 (10*4 + 10*5 + 4*5)  = 2 [ 40 + 50 + 20) = 220cm^2

So.....the surface area  is

220 + 56  - 8 =

268 cm^2

May 3, 2020
#7
+23
+1

thankss! :)

flxm3s  May 3, 2020