Consider a square of side length 2 m. What is the difference of the ar

Consider a square of side length 2 m. What is the difference of the areas of the circumscribed circle and the inscribed circle (in m²) ?

3π/2
π/2
π
This question was previously asked in
UPSC CISF-AC-EXE – 2021
The correct answer is π.
Let the side length of the square be s = 2 m.
The inscribed circle is tangent to all four sides of the square. Its diameter is equal to the side length of the square.
Radius of the inscribed circle (r_in) = s/2 = 2/2 = 1 m.
Area of the inscribed circle = π * (r_in)² = π * (1)² = π m².

The circumscribed circle passes through all four vertices of the square. Its diameter is equal to the length of the diagonal of the square.
Diagonal of the square = s * √2 = 2 * √2 m.
Radius of the circumscribed circle (r_circum) = (diagonal)/2 = (2√2)/2 = √2 m.
Area of the circumscribed circle = π * (r_circum)² = π * (√2)² = π * 2 = 2π m².

The difference of the areas = Area of circumscribed circle – Area of inscribed circle
Difference = 2π m² – π m² = π m².

For a square of side ‘s’, the radius of the inscribed circle is s/2, and the radius of the circumscribed circle is (s√2)/2 = s/√2. The ratio of the radii is (s/√2) / (s/2) = √2, and the ratio of the areas is (Area_circum / Area_in) = (π * (s/√2)²) / (π * (s/2)²) = (s²/2) / (s²/4) = 2. The area of the circumscribed circle is always twice the area of the inscribed circle for any square.
Exit mobile version