Answer:

Step-by-step explanation:
We have
square with sides <em>s = 3cm</em>
four triangles with base <em>b = 3cm</em> and height <em>h = 9cm</em>.
The formula of an area of a square:

The formula of an area of a triangle:

Substitute:

The Surface Area:

Answer:
same side interior
Step-by-step explanation:
Answer:
10
Step-by-step explanation:
When we subtract a negative, it is like adding
+3 - (-7)
+3 +7
10