Stage 8 - Q10 - 6 marks
18806
A prism with right triangular cross-section sides 3, 4 and 5 cm and length 12 cm is cut into three equal shorter prisms, perpendicular to its length. Find the increase in total surface area and explain why the cut lengths are not needed for the increase.
Hint
Count newly exposed faces instead of recalculating every original face.