Sine and Cosine of Complementary Angles Practice Test

On the unit circle, the point at angle $\theta$ is $(\cos\theta,\sin\theta)$. Using the relationship between angles $\theta$ and $\tfrac{\pi}{2}-\theta$, which equation is correct?

In the right triangle, one acute angle measures $35^\circ$. The other acute angle is complementary to it. What is the measure of that complementary angle?