Question

find the side labeled x. x =

Explanation:

Step1: Recall cosine definition in right - triangle

In a right - triangle, $\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}$. Here, $\theta = 60^{\circ}$, the adjacent side to the $60^{\circ}$ angle is 43, and the hypotenuse is $x$. So, $\cos60^{\circ}=\frac{43}{x}$.

Step2: Substitute the value of cosine

We know that $\cos60^{\circ}=\frac{1}{2}$. So, the equation becomes $\frac{1}{2}=\frac{43}{x}$.

Step3: Solve for $x$

Cross - multiply: $x\times1 = 43\times2$. Then $x = 86$.

Answer:

86