Final answer:
In the given question, we are asked to prove the existence of angle 5 based on the given angle measurements. The sum of angles in a triangle is always 180 degrees.
Step-by-step explanation:
In the given question, we are given three angle measurements: 1, 2, and 3. The sum of the angles in a triangle is always 180 degrees. Therefore, we can use this information to prove that there is a triangle with angles 1, 2, and 3. Since the sum of these angles is 180 degrees, we can conclude that there is a third angle, angle 5, in the triangle.