Answer:
The surface area is

Explanation:
we know that
The surface area of the square pyramid is equal to the area of the square base plus the area of its four triangular lateral faces
so
![SA=b^(2) +4[((1)/(2)) (b)(h)]](https://img.qammunity.org/2020/formulas/mathematics/high-school/owf8j4gaqkidi3onjzxyj6n4yk4t1wd9bl.png)
where
b is the length side of the square base
h is the height of each lateral triangular face
we know that
-----> by angle of 45 degrees



Find the value of b

Find the surface area
![SA=12^(2) +4[((1)/(2)) (12)(6)]=288\ cm^(2)](https://img.qammunity.org/2020/formulas/mathematics/high-school/q25symdxrz0uekdgw2h7a8qb88rzq2ffld.png)