Line segment cd is shown on a coordinate grid: a coordinate plane is shown. line segment cd has endpoints 1 comma 2 and 1 comma negative 1. the line segment is rotated 90 degrees counterclockwise about the origin to form c'd'. which statement describes c'd'? a) c'd' and cd are equal in length. b) c'd' is parallel to cd. c) c'd' is half the length of cd. d) c'd' is greater than twice the length of cd.

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