Question

examples.
5om
Example 4 : In Fig. 12.15, two circular flower beds
have been shown on two sides of a square lawn
ABCD of side 56 m. If the centre of each circular
flower bed is the point of intersection O of the
diagonals of the square lawn, find the sum of the
areas of the lawn and the flower beds.
Fig. 12.15​

Answer 1

Answer:

Side of square = 56cm

ΔAOB

AB²=OA²+OB²

56²=r² + r²

56×56=2r²

56×56÷2

⇒r²=56×28

Area of flower bed

⇒ Area of 2 sectors + area of 2 triangles

2×∅÷360 + 2×1/2×b×h

90÷180πr² + r² ( we get 90÷180 by cancellation)

1÷2 × 22÷7 ×56×28 + 56×28

88×28 + 56×28

⇒(88+56)×28

⇒144×28= 4032cm²