Rukhsar painted the outside of the cabinet of measure 1 m × 2 m × 1.5 m. How much surface area did she cover if she painted all except the bottom of the cabinet?
Solution:
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 = 1 m
Height 'h' of the cabinet = 1.5 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 × (1 × 1.5 + 1.5 × 2) + 2 × 1 m²
= 2 × 4.5 + 2 m²
= 11 m²
Therefore the area of the cabinet that was painted is 11 m².
☛ Check: NCERT Solutions for Class 8 Maths Chapter 11
Video Solution:
Rukhsar painted the outside of the cabinet of measure 1 m × 2 m × 1.5 m. How much surface area did she cover if she painted all except the bottom of the cabinet?
Maths NCERT Solutions Class 8 Chapter 11 Exercise 11.3 Question 4
Summary:
Rukhsar painted the outside of the cabinet of measure 1 m × 2 m × 1.5 m. The surface area that she covered if she painted all except the bottom of the cabinet was 11 m².
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