Question

A picture is painted on a ceiling of a marriage hall whose length and breadth are 18 m and 7 m respectively. There is a border of 10 cm along each of its sides. Find the area of the border

Answer 1

Length of the ceiling L = 18 m

Breadth of the ceiling B = 7 m

Area of the ceiling = L × B sq.units

= 18 × 7 m² 

= 126 m²

Width of the boarder W = 10 cm

= `10/100` m

= 0.1 m

Length of the ceiling without border = L – 2W

= 18 – 2(0.1) m

= 18 – 0.2 m

= 17.8 m

Breadth of the ceiling without border = B – 2W

= 7 – 2(0.1) m

= 7 – 0.2 m

= 6.8 m

Area of the ceiling without border = l × b sq.units

= 17.8 × 6.8 m² 

= 121.04 m²

∴ Area of the border = Area of the ceiling – Area of the ceiling without border

= 126 – 121.04 m² 

= 4.96 m²

Area of the border = 4.96 m²