Answer:
143 cm²
Explanation:
There are 3 pairs of sides to this shape,
1 pair is the top and bottom pieces, each has an area of 4(3) = 12 cm², so there are 24 cm² from this pair.
the second pair is the front and back pieces, each has an area of
4(8.5) = 34 cm², so there are 68 cm² from this pair.
the third pair are the side pieces, each has an area of
3(8.5) = 25.5 cm², so there are 51 cm² from this pair.
Al together there are 24 + 68 + 51 = 143 cm²