The circumference of a circle is 18.84 mi. What is the circle's diameter?

a complex number is a number that can be expressed in the form a + bi, where a and b are real numbers, and i is a solution of the equation x2 = −1. because no real number satisfies this equation, i is called an imaginary number. has no real solution, since the square of a real number cannot be negative.

point a is the center of the circle that passes through points e, f, and g and the center of the circle that passes through points x, y, and z.