Answer:
223cm
Step-by-step explanation:
First you want to figure out how many faces the 3D shape has.
This has 5 faces.
Then you find the area of each face.
The front face has an area of 54cm because the length is 6cm and the width is 9cm.
Area = Length x Width
The back face will always have the same area as the front.
54cm + 54cm = 108cm (Front and Back Face)
Now the right side and left side.
The width of the side is 5cm and length is 7cm.
7cm • 5cm = 35cm
Just like the front and back, the right and left side will have the same area.
35cm + 35cm = 70cm
Now the last part.
There is no top face since this is a 3D triangle and not a square and rectangle etc.
So, you don't add it two times like the others.
The bottom's width is 5cm and the length is 9cm
5cm • 9cm = 45cm
Now you add all of it up together to find the surface area.
108cm + 70cm + 45cm = 223cm
Hope this helps dude