Question

Select the correct answer.

Circle F is represented by the equation (x+6)2 + (y+8)2=9. What is the length of the radius of circle F?

A. 3
B. 9
C. 10
D. 81

Answer 1

A

Explanation:

the equation of a circle in standard form is

(x - h)² + (y - k)² = r²

where (h, k ) are the coordinates of the centre and r is the radius

(x + 6)² + (y + 8)² = 9 ← is in standard form

with r² = 9 ( take square root of both sides )

r =
`√(9)` = 3

that is the radius is 3