Question

the radius of bigger circle is 20 CM 3 concentric circles are drawn inside it so that it is divided into four parts of equal area find the area of largest concentric circle

Answer 1

Let r₁ , r₂ and r₃ are radii of three concenteric circles in such a way that r₃ < r₂ < r₁

Now, radius of outermost circle = r = 20 cm
According to question,
πr² - πr₁² = 1/4 πr² { as shown in figure }
⇒πr² - πr²/4 = πr₁²
⇒3πr²/4 = πr₁²
⇒r₁ = √3/2r = √3/2 × 20 = 10√3 cm

Hence, radius of largest concenteric circle = 10√3cm
So, area of largest concenteric circle = π(10√3)² = 300π cm² = 942 cm²

Answer 2

Answer: 300 πcm^2 or 942cm^2

Step-by-step explanation:

Here is the attachment.

Hope this will help you!!