What term describes a line in the plane of a circle that intersects the circle at exactly one point?

The term that describes a line in the plane of a circle that intersects the circle at exactly one point is tangent. A tangent line meets the circle at a single point, which is referred to as a point of tangency. This means that at the point of intersection, the tangent line does not enter or exit the circle; it merely touches the circle's circumference.

The relationship of tangent lines to circles is a significant concept in geometry, especially in the study of circle theorems, where properties related to angles, areas, and other geometric figures involving circles are explored. Understanding the nature of tangent lines helps in solving various geometric problems involving circles and their interactions with other shapes.

In contrast, a secant is a line that intersects the circle at two points, and it does not apply here since we are looking for a line that touches the circle at only one point. A trapezoid is a quadrilateral with at least one pair of parallel sides and does not relate to the properties of a circle. A transversal is a line that intersects two or more lines at different points, which is also not relevant in the context of a circle. Therefore, the defining characteristic of a tangent line makes it the correct term in this scenario.