The figure shows a rectangular park which consists of 1 playground 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 84 m and 21 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 + 84
= 3.14 x 42 + 84
= 131.88 + 84
= 215.88 m
(b)
Area of the shaded region = Area of the rectangle - Barbeque area - Pond area
= 84 x 21 -
12 x 3.14 x 13 x 13 - (
12 x 3.14 x 21 x 21 + 42 x 21 + 2 ( (21 x 21) -
14 x 3.14 x 21 x 21))
= 1764 - 265.33 - (692.37 + 882 + 2 ( - 346.185))
= 1764 - 265.33 - 882
= 616.67 m
2 Answer(s): (a) 215.88 m; (b) 616.67 m
2