### Home > INT2 > Chapter 10 > Lesson 10.1.1 > Problem 10-7

10-7.

Examine the graph of the circle at right.

What is the equation of the circle?

Sketch a right triangle from the origin as in

and label the hypotenuse with the value for the radius. The equation of a circle is directly derived from the Pythagorean Theorem.

On graph paper, sketch the graph of

. What is the radius?The circle with equation

has a radius of .