Question

The circle passes through the point (-1,8). What is it’s radius? Options: A: 3 B: √8 C: √6 D: 2.75

Answer 1

Answer:

B √8

Step-by-step explanation:

Equation of a circle is:

(x − h)² + (y − k)² = r²

where (h, k) is the center and r is the radius.

The center of the circle is (1, 6).

(x − 1)² + (y − 6)² = r²

The circle passes through the point (-1, 8).

(-1 − 1)² + (8 − 6)² = r²

4 + 4 = r²

r = √8