找到你今天要练的题。

\( x^2-4x+y^2-8y-80=0 \) 
In the xy-plane, the graph of the given equation is a circle. If this circle is inscribed in a square. What is the perimeter of the square?

A circle in the xy-plane has its center at (18, 16) and has a radius of 6k. Which equation represents this circle?

The perimeter of an equilateral triangle is 876 centimeters. The three vertices of the triangle lie on a circle. The radius of the circle is \( w\sqrt{3} \) centimeters. What is the value of w?

A circle in the xy-plane has its center at \( \left(-2,\ 2\right) \) . Line t is tangent to this circle at the point \( \left(3,-1\right) \). Which of the following points also lies on line t?

A circle in the xy-plane has its center at (14, 19) and has a radius of 7k. Which equation represents this circle?

In the xy-plane, circle F is defined by the equation \( \left(x+7\right)^2+\left(y+7\right)^2=36 \) . Circle G has the same center as circle F, and the radius of circle G is 2 units greater than the radius of circle F. Circle G is defined by the equation \( \left(x+7\right)^2+\left(y+7\right)^2=p \), where p is a constant. What is the value of p?

\( \left(x+5\right)^2+\left(y+8\right)^2=15^2 \)
In the xy-plane, the graph of the given equation is a circle. What is the length of a radius of this circle?

\( 2x^2+2y^2+tx+ty-78=0 \) 
The given equation, where t is a positive constant, defines a circle in the xy-plane. The radius of this circle is \( \sqrt{41} \) ,what is the value of t?

A circle in the xy-plane has its center at \( \left(-1,\ 1\right) \) . Line t is tangent to this circle at the point \( \left(7,\ -6\right) \). Which of the following points also lies on line t?

Circle A shown is defined by the equation \( x^2+\left(y-5\right)^2=7 \) . Circle B (not shown) has the same radius but is translated 91 units to the right. If the equation of circle B is \( \left(x-h\right)^2+\left(y-k\right)^2=a \) , where h, k, and a are constants, what is the value of \( 4a \) ?

A circle in the xy-plane has center \( (28,\ 5) \)  and y-intercepts \( (0,−16) \) and \( (0,\ 26) \). What is the radius of this circle?

A circle has center O, and points A and B  lie on the circle. The measure of arc AB is 60°, and the length of this arc is 4 inches. What is the circumference, in inches, of the circle?