Answer: (b) The focus of an ellipse is always located precisely at the center of the ellipse.
Step-by-step explanation:
An ellipse is defined as <em>"a closed curve with two axes of symmetry (major axis and minor axis) that results in cutting the surface of a cone by an oblique plane to the axis of symmetry with an angle greater than that of the generatrix with respect to the axis of revolution"</em>. That is why the ellipse is considered a conic figure.
To understand it better: an ellipse has two points on its major axis that are equidistant from the center , which are called foci, being this distance constant. In addition, the eccentricity allows to know how far the foci are from the center of the ellipse.
Therefore, the statement that indicates an ellipse has only one focus located precisely at the center is incorrect.
All sides are equal on a triangle
Answer: 
Work Shown:
Note that (h,k) = (2,-3) is the center and r = 6 is the radius. The last line is not expanded out using the FOIL rule because its common practice to leave it in 
form. This form allows the reader to quickly determine the center and radius (rather than have to do a lot of algebraic steps before hand).
Answer:
c the answer is c
Step-by-step explanation:
Answer:
By sum interior angle of triangle is equal to third exterior angle hence
z = x + y
No find x and y
Sum triangle is 180 degree
