A circle centered at the origin runs through the point (-6, 8). What is the radius of the circle?

Question

A circle centered at the origin runs through the point (-6, 8). What is the radius of the circle?

Answer 1

The radius is the distance from the center of the circle (the origin in this case) to any point on the circle (-6. 8 in this case).

The formula to use is:

r = sqrt(x^2 + y^2)

Substitute -6 and 8 for x and y, then do the math.

Answer 2

You need to use the distance formula:

d=√((x_2-x_1 )^2+(y_2-y_1 )^2 )

note that the radical goes over everything past the equal sign.

That's hard to read.... but basically, you need to figure out the distance from the origin (0,0) and the point on the edge of the circle (-6,8) and you will find the radius.  Label (0,0) as (x_2, y_2) and label (-6,8) as (x_1, y_1).

so you have d=√(0-(-6)^2+(0-8)^2

d=√(6)^2+(-8)^2

d=√36+64

d=√100

d=10

the radius is 10.

Answer 3

The answer is the square root of 8squared + 6squared

=10