AP EAMCET2013MathematicsProperties of Triangles
If in a A B C, 1 a+c + 1 b+c = 3 a+b+c , then C is equal to
Options
- A30^
- B45^
- C60^
- D90^
Correct answer
C. 60^
Step-by-step solution
In A B C 1 a+c + 1 b+c = 3 a+b+c Let C=60^ , then C= 3 aligned & a^2+b^2-c^2=a b & b^2+b c+a^2+a c=a b+a c+b c+c^2 & b(b+c)+a(a+c)=(a+c)(b+c) aligned Divide by (a+c)(b+c) and add 2 on both sides, we get aligned & 1+ b a+c +1+ a b+c =3 & 1 a+c + 1 b+c = 3 a+b+c aligned So, C should be 60^ .