Which of these is the best definition of an ellipse?
o
a. the set of all points in a plane for which the sum of the distances
to two fixed points equals a certain constant
o
b. the set of all points in a plane that are equidistant from a single
point and a line
o
c. the set of all points in a plane that are a certain distance from a
single point
d. the set of all points in a plane for which the difference between
the distances to two fixed points equals a certain constant

proofs involving isosceles triangles often require special consideration because an isosceles triangle has several distinct properties that do not apply to normal triangles.(more about triangle types) therefore, when you are trying to prove that two triangles are congruent, and one or both triangles, are isosceles you have a few theorems that you can use to make your life easier.

step-by-step explanation:

an isosceles triangle has two congruent sides and two congruent angles. the congruent angles are called the base angles and the other angle is known as the vertex angle. ∠bac and ∠bca are the base angles of the triangle picture on the left. the vertex angle is ∠abc

it is x equals 3   plese mark me really need it

step-by-step explanation: