Final answer:
The missing element in the "Event Triangle" is event planners, who work alongside participants and sponsors to ensure the success of an event.
Step-by-step explanation:
Participants, event planners, and sponsors are the three elements of the "Event Triangle". This concept is critical in the context of event planning and management. The event planners' role is organizing and coordinating the event, ensuring that the participant's experience is smooth and enjoyable, while also meeting the objectives of the sponsors who are often funding the event.
Partnering with organizations for event planning can lead to expanded outreach by marketing to multiple networks, promoting diversity among attendees, and combining resources for cost-effectiveness. Moreover, in organizing events that cater to diverse abilities, it is crucial to avoid limiting the diversity of the audience by not labeling events in a way that might restrict the conversation's impact. Lastly, the concept of the iron triangle in interest group politics showcases the symbiotic relationships between groups within policy-making, paralleling the interconnectedness within the Event Triangle.