The figure shows a rectangular park which consists of 1 barbeque in a semi-circle shape and a pond. 4 quarter circles make up the shape of the pond. The length and breadth of the rectangle are 80 m and 40 m respectively.
- Find the perimeter of the pond.
- Find the area of the shaded part. (Take π = 3.14).
(a)
Perimeter of the pond = Circumference of 1 circle + 80
= 3.14 x 40 + 80
= 125.6 + 80
= 205.6 m
(b)
Area of the shaded region = Area of the rectangle - Barbeque area - Pond area
= 80 x 40 -
12 x 3.14 x 14 x 14 - (
12 x 3.14 x 20 x 20 + 40 x 20 + 2 ( (20 x 20) -
14 x 3.14 x 20 x 20))
= 3200 - 307.72 - (628 + 800 + 2 ( - 314))
= 3200 - 307.72 - 800
= 2092.28 m
2 Answer(s): (a) 205.6 m; (b) 2092.28 m
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