Relations and Functions

Question

Answer

U = Set of alll triangles = {x : x is a triangle}

A = Set of all trinalges with at least one angle different

= {x : x is a triangle and x has at least one angle different

∴ A' = U - A

= {x : x is a triangle} - {x : x is a triangle and x at least one angle different }

= {x : x is a triangle and no angle is different }

= {x :x is a triangle and x has all angles equal }

= Set of equilateral triangles.

Hence, A' = Set of all equlateral triangles.