Question

Let A, r ,C denote the area, radius and Circumference respectively of a circle.write a relation A,r and C.

Answer 1

Step-by-step explanation:

Area A=πr^2

Circumference C=2πr

Therefore r=C/2π

A=π(C/2π)^2

A=(C^2)/4π

Answer 2

Answer:

Let C and A be the circumference and the area of a circle respectively. If xC is the circumference of another circle whose area is 2A, then x equals

Since, C r & A = πr2

By given, circumference & area of new circle,

C=xC

& A₁ = 2A

⇒ π(1₁)² = 2(πr²)

⇒r₁ = √2r

Now, equating the circumferences, C₁ xC ⇒ 2лr₁ = x(2) → √√2rx xr

⇒x= √2