In any triangle, the sum of all three interior angles is always $180^\circ$.

Given that:

• $\angle A = 72^\circ$
• $\angle B = 55^\circ$

We can calculate $\angle C$ as follows:

$\angle C = 180^\circ - \angle A - \angle B$ $\angle C = 180^\circ - 72^\circ - 55^\circ = 53^\circ$

Thus, the measurement of $\angle C$ is $53^\circ$.

The correct answer is D. 53°.

Would you like more details or have any questions?

Here are some related questions you might find helpful:

1. How do you find the third angle of a triangle?
2. What are the properties of the angles in a triangle?
3. Can a triangle have two angles greater than 90 degrees?
4. How do you classify triangles based on their angles?
5. What is the difference between an obtuse and an acute triangle?

Tip: Always remember, the sum of the interior angles of a triangle is 180°.