A girl painted the outside of the cuboid shaped cabinet of measure 2 m × 3 m × 2.5 m. How much surface area did she cover if she painted all except the bottom of the cabinet?
The surface area of the bottom of the cuboid will be subtracted from the total surface area of the cabinet.
From the given figure,
Length 'l' of the cabinet = 2 m
Breadth 'b' of the cabinet = 3 m
Height 'h' of the cabinet = 2.5 m
Area of the bottom of cabinet = l × b
Since the cabinet is cuboidal in shape,
Total surface area of the cabinet = 2(l × b + b × h + h × l)
Area of the cabinet that was painted = (Total surface area of the cabinet) - (Area of bottom of the cabinet)
= 2(l × b + b × h + h × l) − l × b
= 2(b × h + h × l) + l × b
= 2 × (3 × 2.5 + 2.5 × 2) + 2 × 3 m²
= 2 × 12.5 + 6 m²
= 31 m²
Therefore the area of the cabinet that was painted is 31 m².