CONCEPT PREVIEW Name the corresponding angles and the corresponding sides of each pair of similar triangles. (HK is parallel to EF.)

Similar triangles are triangles that have the same shape but may differ in size. This means that their corresponding angles are equal, and their corresponding sides are in proportion. Understanding the properties of similar triangles is essential for identifying corresponding angles and sides, especially when dealing with parallel lines.

Corresponding angles are pairs of angles that are in the same relative position at each intersection where a straight line crosses two others. In the context of parallel lines, when a transversal intersects them, the angles formed on the same side of the transversal and in corresponding positions are equal. This concept is crucial for establishing relationships between angles in similar triangles.

Parallel lines are lines in a plane that never meet and are always the same distance apart. When two lines are parallel, the angles formed by a transversal intersecting them create specific angle relationships, such as corresponding angles being equal. Recognizing parallel lines is vital for solving problems involving similar triangles and their properties.