A B C D is a square. Γ 1 is a circle that circumscribes A B C D (i.e. Γ 1 passes through points A , B , C and D ). Γ 2 is a circle that is inscribed in A B C D (i.e. Γ 2 is tangential to sides A B , B C , C D and D A ). If the area of Γ 1 is 1 0 0 , what is the area of Γ 2 ?
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Let the side of the square be a. Radius of the circumscribed circle =half the diagonal of the square=√2a/2. Radius of the inscribed circle=half the side of the square=a/2. Area of the circumscribed circle=2a^2/4 *π=100 ⇒a^2/4=50/π. Area of the inscribed circle=a^2/4 * π=50/π * π=50
Both circle have their centers on the center of the square. Thus the radius of the inscribed circle is equal to the side length of the square ABCD (call it a ). The circumscribing circle has a radius equal to a 2 . Thus the ratio of the areas of the circumscribing circle to that of the inscribed circle = 2 1 . The area of the inscribed circle is therefore = 2 1 × 1 0 0 = 5 0
Let side of the square be a. The circumscribed circle Γ1 has an area of 100 and clearly it's radius is half of the diagonal of the square i.e. x=a/2^0.5
Therefore 100= pi * x * x (i)
Let area of the inscribed circle be y. Clearly the radius of this circle is half the side of the square.
z=a/2
y= pi * z * z (ii)
Dividing (i) and (ii)
we get y=50 sq. unit
let A B C D has side length of x , Then Γ 1 will have area π ( 2 2 x ) 2 = 2 π x 2 ,and Γ 2 will have area π ( 2 x ) 2 = 4 π x 2 .Now, Γ 2 Γ 1 = 2 . Thus the area of Γ 2 is 2 1 0 0 = 5 0
Let the side of the square be a units. Radius of outer circle = a/(sqrt. 2) Equating to area = 100, we get pi*(a^2) = 200
Radius of inner circle = a/2 Area = pi (a^2)/4 Substituting the value of pi (a^2); we get area = 50 units
Γ 1 and Γ 2 have the same centre. assume it's O and the radius Γ 2 is r 2 , radius of Γ 1 is r 1 . The radius of the Γ 1 is a half of square ABCD sides.The radius of Γ 2 is a half of square ABCD diagonal. then r 2 = 2 2 r 1 ⇔ r 2 2 = 2 r 1 2 . We know area of Γ 1 is π r 1 2 = 1 0 0 . Hence, area of Γ 2 is π r 2 2 = 2 π r 1 2 = 2 1 0 0 = 5 0 . *p.s. sorry my english realy bad
Let O be the center of the circles, and E be the perpendicular from O to A B . Γ 1 and Γ 2 are similar by a ratio of O E O A = 2 . Hence, the area of Γ 2 is ( 2 ) 2 1 0 0 = 5 0 .
Let side of the square be a. The circumscribed circle Γ1 has an area of 100 and clearly it's radius is half of the diagonal of the square i.e. x=a/2^0.5 Therefore 100= pi * x * x (i) Let area of the inscribed circle be y. Clearly the radius of this circle is half the side of the square. z=a/2 y= pi * z * z (ii) Dividing (i) and (ii) we get y=50 sq. un
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Suppose the length of each side of A B C D is 2 s
By drawing a line from center point to point A and a line from center point perpendicularly to A B , we have a right triangle and get the radius of Γ 1 is s 2 and Γ 2 is s
Here we have
π ( s 2 ) 2 = 1 0 0
2 π s 2 = 1 0 0
and get
π s 2 = 5 0 which is the area of Γ 2