If length, breadth and height of a cuboid are increased by 20%, what is the percentage increase in the the total surface area of cuboid? [3 MARKS]
Concept: 1 Mark
Formula: 1 Mark
Application: 1 Mark
Let l,b,h be the original dimensions
New dimensions
=(1.2l),(1.2b),(1.2h)
New total surface area
=2(lb+bh+hl)
=2(1.44lb+1.44bh+1.44hl)
=1.44×2(lb+bh+lh)
⇒44% increase in the total surface area.