Hello!
The answers are:
For the first image: Total surface area is [tex]880cm^{2}[/tex]
For the second image: Total surface area is [tex]465.6cm^{2}[/tex]
Why?
First Image
There are three rectangles to take into consideration for the total surface area calculation:
First rectangle,
[tex]Length=10cm+8cm+10cm+8cm=36cm\\Width=20cm\\ Area=36cm*20cm=720cm^{2}[/tex]
Second and third rectangles have equal dimensions,so:
[tex]Area=2(8cm*10cm)=160cm^{2}[/tex]
So, the total surface area will be
[tex]TotalArea=720cm^{2}+160cm^{2}=880cm^{2}[/tex]
Second Image
There is: a rectangle composed of three rectangles and 4 right triangles, so:
Rectangle,
[tex]Length=12cm+12cm+12cm=36cm\\Width=6cm\\Area=36cm*6cm=216cm^{2}[/tex]
Triangles,
[tex]Height=10.4cm\\Base=6cm\\Area=4(10.4cm*6cm)=4*62.4cm^{2}=249.6cm^{2}[/tex]
So, the total surface area will be:
[tex]TotalArea=RectangleArea+TrianglesArea=216cm^{2}+249.6cm^{2}\\TotalArea=465.6cm^{2}[/tex]
Have a nice day!
