Question

The equation for the circle below is x^2+ y^2= 81. What is the length of the
circle's radius?

Answer 1

Answer: 9

Step-by-step explanation: The standard form of an equation of a line:

(x-h)^2+(y-k)^2=r^2

(h, k) - center

r - radius

We have the equation:

x^2+y^2=81\Rightarrow(x-0)^2+(y-0)^2=9^2

Therefore

center: (0, 0)

radius: r = 9

Answer 2

9

Explanation:

The standard form of an equation of a line:

`(x-h)^2+(y-k)^2=r^2`

(h, k) - center

r - radius

We have the equation:

`x^2+y^2=81\Rightarrow(x-0)^2+(y-0)^2=9^2`

Therefore

center: (0, 0)

radius: r = 9