Answer:
260 in²
Step-by-step explanation:
<u>1) Find the total area of the triangular sides</u>

Plug in 10 in as the base and 8 in as the height

Multiply the area by 4 (for the 4 triangular surfaces)

Therefore the total area of the triangular sides is 160 in².
<u>2) Find the area of the square base</u>

Plug in 10 as the length

Therefore, the area of the square base is 100 in².
<u>3) Add the areas together</u>
100 in² + 160 in²
= 260 in²
Therefore, the surface area of the solid is 260 in².
I hope this helps!