Exercise 17 Page 384

Let's start by sketching an arbitrary plane $P.$

Since line $\ell$ is to intersect $\mathcal{P}$ at only one point, $\ell$ cannot be completely contained within $P.$ If the line was in the plane, they would intersect at infinitely many points. Thus, we can sketch $\ell$ as a line that intersects plane $\mathcal{P}$ at exactly one point by letting it approach $\mathcal{P}$ at an angle.