What’s the total surface area?

208 in²

Explanation:

64 in² for the base (8•8)

Area of triangle = 1/2bh

For one triangle side:

1/2 (9•8)

1/2 (72)

36 in²

Multiply 36 in² • 4 sides = 144 in²

144 in² + 64 in² = 208 in²

12r - 8 - 12

you have to combine like terms. below i have bolded the like terms:

12r - 8 - 12

together it combines to:

12r - 20

hope this !