Elitmus
Exam
Logical Reasoning
Number Series
The circle O having a diameter of 2 cm,has a square inscribed in it.Each side of the square is then taken as a diameter to form 4 smaller circles O".Find the total area of all four O" circles which is outside the circle O.
Options:-
1)2
2)pi-2
3)2-pi/4
4)2-pi/2
Read Solution (Total 7)
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- 1)2 ..required area = area of 4 semicircles formed by all four O" circles -( area of circle O -area of square)= 4 * Pi *(root 2/2)(root 2 /2)-( Pi*1*1 -root 2 * root 2)=Pi-(Pi-2)= 2
- 11 years agoHelpfull: Yes(31) No(1)
- side of square= sqrt(2) = diameter of smaller circles
area of external circle= pi(1*1)=pi
area of square=2
area of a small circle= pi*((sqrt(2))/2)^2 = pi/2
area of all 4 circles= 2pi
area of circles outside the major circle= 1/2(area of all 4 circles) - ((area of major circle)-area of square))
=pi-(pi-2) = 2 - 11 years agoHelpfull: Yes(11) No(0)
- yeah bro u r right the correct answer is 1)2
- 11 years agoHelpfull: Yes(6) No(0)
- 1)2 is the right option
- 11 years agoHelpfull: Yes(4) No(0)
- i think the correct answer is 2)pi-2
- 11 years agoHelpfull: Yes(4) No(7)
- diameter of circle will become diagonal of Square ie 2 cm.
side of square=square root of 2.
area of 4 circles is =2 pi.
are outside of square=pi.
we want out side part Of circle:
pi-(pi-2)=2
- 11 years agoHelpfull: Yes(4) No(0)
- The first thing I did was to find the side of the square inscribed in the circle,
as the diameter of the circle will be the diagonal of the square, this will form two 45 45 90 right triangles with a hypotenuse of 2.
Since s = ssqrt(2), 2 = s(sqrt(2).
divide 2 by sqrt(2) = 2/sqrt(2)
Multiply the numerator and denominator by sqrt(2) to obtain 2(sqrt(2)/2 for each side of the square, or sqrt(2)
Now, these are being used as diameters for four more circles, so we determine the radius of each one of the four to be sqrt(2)/2
So this value squared times pi will be the area of each circle, or 2/4 = 1/2 times pi = 1/2 pi for each circle times four circles results in 2 pi as the area for the four circles combined.
The area of the original circle is pi r^2, radius being 1 so the area of the original circle will come to 1pi.
So, since the outer circles obviously cover the original circle completely, the area outside the original should be 2pi minus pi, or one pi.
- 11 years agoHelpfull: Yes(0) No(1)
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