Answer:
Step-by-step explanation:
area of triangular face = ½·3·4 = 6 cm²
area of 3 by 7 face = 3×7 = 21 cm²
area of 5 by 7 face = 5×7 = 35 cm²
area of 4 by 7 face = 4×7 = 28 cm²
total surface area = 2×6 + 21 + 35 + 28 = 96 cm²
