Answer:
17F
Step-by-step explanation:
(-2F) +(19F) = 17F
The signed numbers add in the usual way. (If you really can't do this in your head, a calculator can help.)
I believe the answer is 47.
To find the lateral area you will find the area of all 4 faces that are perpendicular to the base.
You will multiply the side by the length (front/back) and the side by the width (sides).
12 x 8 = 96
12 x 2 = 24
120 square inches x 2 = 240 square inches
The lateral area is 240 square inches.
The area of the base is 8 x 2 = 16 square inches.
16 x 2 = 32 square inches
240 square inches + 32 square inches = 272 square inches is the surface area.
