Answer:
(a) See net below
(b) 38 cm^2
Explanation:
(a) see completed net below.
It's like a pizza box when finishd.
Fold the two sides (left, right, 1*3) up.
Fold the bottom part added up to form a side.
Fold the very bottom rectangle to form the top face.
(b) Total surface area
= top and bottom faces of 12 cm^2 each+ 2 sides of 3 cm^2 + 2 sides of 4 cm^2 each
= 2*12 + 2*3 + 2*4
= 24 + 6 + 8
= 38 cm^2