Answer:
33 units²
Explanation:
Use the formula for the surface area of a square pyramid:
![S.A.=b^2+2bh](https://img.qammunity.org/2023/formulas/mathematics/high-school/h3x9khw02xpyypu7lyx371naykizu4otrs.png)
Where b is the base, and h is the slant height.
Substitute:
![S.A.=3^2+2(3)(4)\\S.A.=9+24\\S.A.=33](https://img.qammunity.org/2023/formulas/mathematics/high-school/a3tj8hp87dw0s054kv9samxm9ejo1mry0z.png)
Or use the net and solve for the area of each shape:
Area of square:
![A_s=3^2\\A_s=9](https://img.qammunity.org/2023/formulas/mathematics/high-school/f564eokw4fmvt2j73m801b3qx8x9qex1gv.png)
Area of 4 triangles:
![A_t=(bh)/(2)\\A_t=((3)(4))/(2)\\A_t=(12)/(2)\\A_t=6\\4A_t=(4)(6)\\4A_t=24](https://img.qammunity.org/2023/formulas/mathematics/high-school/t33ac9uazmimz8r2x0fcbm3f05qi13dop3.png)
Add both results up:
![S.A.=24+9\\S.A.=33](https://img.qammunity.org/2023/formulas/mathematics/high-school/ry2gitdav8o2sucdoe04zyotf5tz6rldvm.png)
And put units² at the end.