Answer
$$\sin35^\circ=\cos55^\circ$$
18 is matched with B.
Work Step by Step
$$\sin35^\circ$$
We know that $35^\circ+55^\circ=90^\circ$.
Now remind yourself of Cofunction Identity for sines and cosines, which state
$$\sin\theta=\cos(90^\circ-\theta)$$
Thus, $$\sin35^\circ=\cos(90^\circ-35^\circ)=\cos55^\circ$$
$\cos55^\circ$ is choice B. 18 is matched with B.
