1. Find the area of the shaded region in fig(i) below. If radii of the two concentric circles with centre O are 7 cm and 14 cm respectively and angle AOC = 40⁰.
2. Find the area of the shaded region in the figure below. in fig(ii) below where ABCD is a square of side 10 cm and semi-circles are drawn with each side of the square as diameter. [Use \pi = 3.14]
3. In fig(iii), O is the centre of the circle with AC = 24 cm, AB = 7 cm and angle BOD = 90⁰. Find the area of the shaded region in the figure below. [Use  \pi = 3.14]
PLEASE ITS VERYY URGENT!!! THNX VRY MUCH..

2

Answers

The Brainliest Answer!
2015-03-12T09:07:07+05:30
Make sector OEFC and ABED. Now,
radius of inner circle=7cm
radius of outer circle=14cm
area of shaded region= area of sector OAFC - area of sector OBED
(40/360*22/7*14*14) - (40/360*22/7*7*7) (since area of sector= n/360*22/7*r*r)
(1/9*22/7*14*14) - (1/9*22/7*7*7)
616/9 - 154/9
462/9
154/3 sq cm

ii) Side of square=10cm
Given that side of square is taken as diameter 
=> radius of circle=10/2=5cm
4 shaded region makes a circle
=>area of shded region=area of circle
= 3.14*5*5
=3.14*25
=78.5 sq cm

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2015-03-15T12:19:45+05:30
Make sector OEFC and ABED. Now,
radius of inner circle=7cm
radius of outer circle=14cm
area of shaded region= area of sector OAFC - area of sector OBED
(40/360*22/7*14*14) - (40/360*22/7*7*7) (since area of sector= n/360*22/7*r*r)
(1/9*22/7*14*14) - (1/9*22/7*7*7)
616/9 - 154/9
462/9
154/3 sq cm

ii) Side of square=10cm
Given that side of square is taken as diameter 
=> radius of circle=10/2=5cm
4 shaded region makes a circle
=>area of shded region=area of circle
= 3.14*5*5
=3.14*25
=78.5 sq cm
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