ABC is an equilateral triangle. AD is perpendicular to BC. Prove that  `AB^(2) + BC^(2) + CA^(2)  =4
Channel: Doubtnut
Date: 2020-05-09

ABC is an equilateral triangle. AD is perpendicular to BC. Prove that  `AB^(2) + BC^(2) + CA^(2)  =4AD^(2)`