Which one does NOT belong?

Exercise and reference answers

Questions

1. Items

   1. All circles
   2. All squares
   3. All triangles
   4. All equilateral triangles

   Reason

   Triangles in general are not similar to each other; only equilateral ones are. Circles and squares always are.

   Odd item

   All triangles

2. Items

   1. Same shape
   2. Corresponding angles equal
   3. Corresponding sides in ratio
   4. Same area

   Reason

   Similar figures need not have the same area, since they may differ in size.

   Odd item

   Same area

Instructions

Tap the item that does not belong with the rest.

Explanation