A triangle has sides A, B, and C. Sides A and B are of lengths $14$ $14$ and $9$ $9$ , respectively, and the angle between A and B is $\frac{5 π}{12}$ $(5pi)/12$ . What is the length of side C?

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Answer 1 · 2018-02-03T12:31:16

The length of side C is $14.55$ $14.55$ unit

Angle between Sides $A and B$ $A and B$ is

$∠ c = \frac{5 π}{12} = \frac{5 \cdot 180}{12} = 75^{0}$ $/_c= (5pi)/12=(5*180)/12=75^0$ Sides $A = 14, B = 9$ $A=14 , B=9$

Cosine rule: (for all triangles) $A^{2} + B^{2} - 2 A B cos (c) = C^{2}$ $A^2 + B^2 − 2AB cos(c) = C^2$

$:. C^2=14^2 + 9^2 − 2*14*9*cos(75)$ or

$C^2~~211.78 :. C ~~ 14.55 (2dp)$

The length of side C is $14.55$ unit [Ans]

A triangle has sides A, B, and C. Sides A and B are of lengths 141414 and 999, respectively, and the angle between A and B is (5pi)/12 5π12(5pi)/12 . What is the length of side C?