Prove that in triangle ABC b²=a²+c²-2ca cosB
Please don't spam
it's really urgent
please answer
Share
Prove that in triangle ABC b²=a²+c²-2ca cosB
Please don't spam
it's really urgent
please answer
Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Verified answer
Answer:
As we have ABC is a triangle hence a+b+c=0
So, a+b=−c
Squaring on both sides,
(a+b)(a+b)=(−c)(−c)
b2+a2+2abcos(π−C)=c2 [Using dot product ]
b2+a2+2ab(−cosC)=c2
c2=a2+b2−2abcosC
please mark my answer as brainliest