The total surface area of the blue prism is: 161 cm²
How to find the total surface area?
The formula for total surface area is:
TSA = 2(LW + LH + WH)
Let us instead find the area of each face and add them all. Thus:
Front area = 6 * 5 = 30 cm²
Back area = 6 * 5 = 30 cm²
Right Area = 6 * 5 = 30 cm²
Left Area = 6 * 5 = 30 cm²
Bottom Area = 5 * 5 = 25 cm²
Top Area = (5 * 5) - (3 * 3) = 16 cm²
Total surface area = 30 cm² + 30 cm² + 30 cm² + 30 cm² + 25 cm² + 16 cm²
Total surface area = 161 cm²