Question

In the standard (x,y) coordinate plane, what is the area of the circle x^2 + y^2 =169?

Answer 1

Answer:

169π

Step-by-step explanation:

circle eq: (x-a)²+(y-b)²=r², where (a,b) is center and r is radius

r²=169

r = ±13

since a radius length must be positive, r = +13, not -13

A of circle: πr²

r = 13

169π

given that the circle eq has r², you could've noticed that you can take the constant in the circle eq and multiply that by π to get the same answer