Final answer:
Coworkers are not considered one of the three key types of relationships according to Sternberg's Triangular Theory of Love, which includes the components of intimacy, passion, and commitment.
Step-by-step explanation:
When discussing the three key types of relationships, the options given are romantic partners, coworkers, family, and friends. According to the theory presented, which involves proximity as a significant factor in forming relationships, coworkers do not inherently fall into one of the primary categories of relationships defined by Sternberg's Triangular Theory of Love. Sternberg identified intimacy, passion, and commitment as the components forming different types of love relationships. The three foundational relationship types that align with these components are typically romantic partnerships, friendships, and familial bonds. Therefore, among the options provided, 'coworkers' is not one of the three key types of relationships as defined by Sternberg's love components.