Answer:
I only know the first one.
The surface area of the prism is 900 cm2
Explanation:
To solve the surface area, we need to find the area of the SURFACE not the inside of the cube. Lets do the rectangles first.
28 x 13 = 364
28 x 5 = 140
28 x 12 = 336
1 1
336
+ 140
364
-------------
8 4 0
Now lets do the triangles.
Remember! To find the area of a triangle, you have to do Base x Height x 1/2 because it's half a rectangle.
(The triangles have the same area)
12 x 5 x 1/2 = 30
12 x 5 x 1/2 = 30
30
+ 30
--------
60
The last step is to add the areas of the triangles and the rectangles.
1
840
+ 60
------------
900 cm2
The answer is 900cm2
This Is not copy pasted, I actually put in all this effort.
Hope this helps :) And have a wonderful day! :D