isi-entrance 2016 Q11

isi-entrance · India · UGA 4 marks Sine and Cosine Rules Find an angle using the cosine rule
The sides of a triangle are given to be $x ^ { 2 } + x + 1, 2 x + 1$ and $x ^ { 2 } - 1$. Then the largest of the three angles of the triangle is
(A) $75 ^ { \circ }$
(B) $\left( \frac { x } { x + 1 } \pi \right)$ radians
(C) $120 ^ { \circ }$
(D) $135 ^ { \circ }$
The sides of a triangle are given to be $x ^ { 2 } + x + 1, 2 x + 1$ and $x ^ { 2 } - 1$. Then the largest of the three angles of the triangle is\\
(A) $75 ^ { \circ }$\\
(B) $\left( \frac { x } { x + 1 } \pi \right)$ radians\\
(C) $120 ^ { \circ }$\\
(D) $135 ^ { \circ }$