I know it's easy but pls help.

7

Step-by-step explanation:

36+42= 6 x 13

which is true

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