9) A rectangular hall has semicircular walls on its
two sides, as shown. If the dimensions of the
rectangular portion are 12 metres and 7 metres
calculate the area covered by the hall.
Answers
Answered by
4
Answer:
122.5 m²
Step-by-step explanation:
Area of figure = Area of rectangle + area of 2 semi-circle of diameter(=breadth).
Radii of semi-circle = breadth/2 = 7/2
Area of 2 semi-circle = 2[ 1/2 π(7/2)² ]
= 38.5 m²
Area of rectangle = length x breadth
= 12 x 7 = 84 m²
Total area covered by the hall = 38.5 + 72 m² = 122.5 m²
Answered by
12
area covered by the hall is 122.5 m²
length of rectangle , l = 12m
breadth of rectangle, b = 7m
radius of semicircle, r = 7/2 m = 3.5 m
area covered by the hall = 2 × area of semicircular + area of rectangle
= 2 × πr²/2 + l × b
= πr² + l × b
= 22/7 × (3.5)² + 12 × 7
= 22 × 0.5 × 3.5 + 84
= 11 × 3.5 + 84
= 38.5 + 84
= 122.5 m²
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