10. Exercise Problem V

In a classroom, $4$ friends are seated at the points $A, B, C$ and $D$ as shown in the following figure. Champa and Chameli walk into the class and after observing for a few minutes Champa asks Chameli, “Don’t you think $ABCD$ is a square?” Chameli disagrees.  Using distance formula, find which of them is correct.

 

 

Ans:

 

Champa was wrongcorrect