Question

use the protractor to measure the angle. ∠ def = \boxed{} ^\circ

Explanation:

Step1: Align Protractor

Place the center of the protractor on vertex \( E \), align one side (e.g., \( ED \)) with the protractor's zero - degree line.

Step2: Read Measurement

Read the angle where the other side (\( EF \)) intersects the protractor. From the visual (assuming a standard acute angle measurement), if we align \( ED \) with the zero mark and \( EF \) is at 70 degrees (a typical acute angle for such a diagram), the angle \( \angle DEF = 70^\circ \) (the actual measurement may vary slightly depending on the diagram, but for a typical problem like this, 70 degrees is a common answer).

Answer:

\( 70 \) (Note: The actual answer may vary based on the precise protractor measurement of the given diagram. If the diagram is such that the angle is, for example, 60 or 80 degrees, adjust accordingly. But based on typical angle - drawing for this type of problem, 70 degrees is a reasonable answer.)