Circles and Coordinates : Distance from the Center

I have solved this question and I would like to know if I am correct.
" A pizza shop delivers to all customers within a circle determined by the equation
X squared + Y squared = 400, If the pizza shop is at coordinates (0,0), would they delvier to someone who lives at coordinates (16,-11)
x + y = 20
Therefore the radius of the circle is 20 units.

... All we have done so far is a series of coordinate transformations ... the distance of an arbitrary point at coordinates alpha and r to the center of the circle. ...

... Ask the user to specify the x- and y-coordinates of a ... x-coordinate of the center @param y the y-coordinate of the ... return true if the point is inside the circle...

... things as points, lines, planes, angles, circles, and triangles ... A circle can be described with any given ... geometry and utilization of coordinates establishes the. ...

... distant from the point , and that distance is R ... is to multiply the x and y coordinates in equation ... parametric equation of an origin-centered circle with radius ...

... m and the vertical height gained in moving this distance is 20 m ... Let r - radius of the circle. ... t, then POM = t. Let (x,y) be the co-ordinates of the ...

... not sufficient as any other point on the circle with A ... in two dimensions is the Cartesian xy coordinate system in ... by means of its x and y coordinates as shown ...

... rho = M/A (2.1). The area is half that of a circle of radius R and is thus: ... In terms of polar coordinates an area element dA is: ... The y coordinate is: ...

... spreadsheet so that it calculates the 24 polar coordinates for any ... Since you can rotate a circle and start wherever, this ... Circumference of circles are provided ...

... can approximate the particle's path by a circle of slowly ... n By definition, Σ(mαyα)/M = Y coordinate of the ... in the values of X and Z coordinates (because PE ...

... Its basically the diameter of the circle. ... varies as the inverse fifth power of distance r from ... Central Forces in Polar Coordinates Let's use the Lagrangian: ...