Question

In a triangle abc ,angle B is obtuse angle,angle D=90° prove that ac^2=ab^2+bc^2+2BC×BD

Answer 1

Answer:

In the right angle triangle ABD, we have 

        AD² = AB² - BD²

In the right angle triangle  ACD we have 

       AD² = AC² - CD²

So    AC² - CD²  = AB² - BD²

       =>  AC² = AB² + CD²  -  BD²

       =>         = AB² + (CD + BD)* (CD - BD )

                    = AB² + BC * [(BC - BD) - BD]

                    = AB² + BC * [ BC - 2 BD ]

                      = AB² +BC² - 2 BC * BD

Hope This Helps :)

Answer 2

Hii.. Please check the attachment..

Please mark as Brainliest..