Question

Can u explain how to solve this?

Answer 1

Answer: B.pi/2

ABCD is a square

=> Δ ABD is a isosceles right triangle at A

using pythago theorem, we have:

AB² + AD² = BD²

=> 2AD² = 4

⇔ AD² = 2

⇒ AD = √2

through O, draw EF parallel to AD and BC

=> EF is diameter

because EF//AD => EF = AD = √2 (because circle O is inscribed the square ABCD)

=> the area of the circle is
`S=((√(2))^(2) )/(4).\pi =(\pi )/(2)`

Explanation: