Question

What is the radius of a circle with the given center C that passes through the given point Z?

C (0, 0); Z (-8, 0)


A. 4
B. SQRT(61)
C.8
D. 5
E. SQRT(173)
F. SQRT(180)

Answer 1

Use the Pythagorean theorem to find the distance between the two points. That's your radius.

Answer 2

Hint: The difference between the x values of two points is the length of one of the sides of a right triangle, the difference between the y values is the length of the other side. The length of the hypotenuse is the distance between the two points.

Answer 3

Sorry, I didn't pay attention to the points. They're both on the x-axis, so the radius of the circle is 8.

Answer 4

glad you caught yourself I was about to mention it.

Answer 5

if a point lies on a circle then the distance from that point to the center is the radius. For most points you would use the distance formula to find this distance but this one is easier because it lies on the x-axis, 8 units away from the center