A triangle has sides A, B, and C. Sides A and B are of lengths $3$ and $7$ , respectively, and the angle between A and B is $pi/6$ . What is the length of side C?

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Answer 1 · 2017-07-08T17:13:58

The length is $=4.65u$

The side $A=3$

The side $B=7$

The angle between $A$ and $B$ is $=1/6pi$

We apply the cosine rule to the triangle

$C^2=A^2+B^2-2ABcos hat(C)$

$=3^2+7^2-2*3*7*cos(1/6pi)$

$=9+49-42cos(1/6pi)$

$=21.6$

$C=sqrt21.6=4.65$

A triangle has sides A, B, and C. Sides A and B are of lengths 33 and 77, respectively, and the angle between A and B is pi/6pi/6. What is the length of side C?