How to find the equation of a circle

Practice Questions

ACT Math › How to find the equation of a circle

Page 1 of 3
10 of 28
1

Find the equation of the circle with center coordinates of and a radius of .

2

A circle with a radius of five is centered at the origin. A point on the circumference of the circle has an x-coordinate of two and a positive y-coordinate. What is the value of the y-coordinate?

3

The endpoints of a diameter of circle A are located at points and . What is the area of the circle?

4

A circle has its origin at . The point is on the edge of the circle. What is the radius of the circle?

5

A circle exists entirely in the first quadrant such that it intersects the -axis at . If the circle intersects the -axis in at least one point, what is the area of the circle?

6

We have a square with length 2 sitting in the first quadrant with one corner touching the origin. If the square is inscribed inside a circle, find the equation of the circle.

7

What is the equation for a circle of radius 12, centered at the intersection of the two lines:

y_1 = 4_x + 3

and

y_2 = 5_x + 44?

8

In the standard coordinate plane, what is the radius and the center of the circle ?

9

A circle is centered on point . The area of the circle is . What is the equation of the circle?

10

Which of the following equations describes all the points (x, y) in a coordinate plane that are five units away from the point (–3, 6)?

Page 1 of 3
Return to subject