Question

How do you find the circumference and area of the circle whose equation is `x^2+y^2=36`?

Answer 1

`C = 12pi ≈37.7`
`A = 36pi ≈ 113`

Explanation:

The equation of a circle in the form `x^2 + y^2 = r^2`

represents a circle , centre ( 0 , 0 ) and radius r

the equation `x^2 +y^2 = 36 color(black)(" is in this form ")`

and therefore has a radius = 6

hence circumference, C `= 2pir = 12pi ≈ 37.7`

and area , A `= pir^2 = 36pi ≈113`