A rectangular hall is 18 m long and 12 m wide. A carpet border 1.5 m wide runs all around the INSIDE edge of the hall, leaving a bare rectangle in the middle. Find the area covered by the border (in m²).

Question

Accepted Answer

81. Hall = 18 × 12 = 216 m². The bare middle is (18 − 3) × (12 − 3) = 15 × 9 = 135 m², because 1.5 m comes off BOTH ends of each dimension. Border = 216 − 135 = 81 m². Multiplying the hall perimeter by the width (60 × 1.5 = 90) double-counts the corners; subtracting 1.5 only once from each side gives 42.75.

A rectangular hall is 18 $m$ long and 12 $m$ wide. A carpet border 1.5 $m$ wide runs all around the INSIDE edge of the hall, leaving a bare rectangle in the middle. Find the area covered by the border (in $m^{2}$ ).

Step-by-Step Solution

Key idea: Parallelogram area

Master this chapter in 30 minutes a day.

More Class 7 Perimeter and Area practice

A rectangular hall is 18 m long and 12 m wide. A carpet border 1.5 m wide runs all around the INSIDE edge of the hall, leaving a bare rectangle in the middle. Find the area covered by the border (in m2).

Step-by-Step Solution

Key idea: Parallelogram area

Master this chapter in 30 minutes a day.

More Class 7 Perimeter and Area practice

A rectangular hall is 18 $m$ long and 12 $m$ wide. A carpet border 1.5 $m$ wide runs all around the INSIDE edge of the hall, leaving a bare rectangle in the middle. Find the area covered by the border (in $m^{2}$ ).