What is the surface area of the figure shown?

You have two main shapes here:
So you have a square and a traingle
Surface area is the area of all the OUTSIDE surfaces that make up the large figure
So in total you have 5 Squares and 4 triangles. Does this make sense?

So area of a square is l*w
area of a triangle is (b*h)/2

So now we can come up with a final equation:
Surface Area of figure=
5*(l*w)+4*((b*h)/2)
Does this make sense?
Plug in and solve

Yes i could be the length of the triangle