Question

use the protractor to measure the angle. ∠ def = □°

Explanation:

Step1: Align protractor with angle

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

Step2: Read the angle measure

Read the degree mark where the other side (\( EF \)) intersects the protractor. From the visual (assuming standard angle measurement), the angle \( \angle DEF \) is \( 70^\circ \) (this is a typical angle measure for such a diagram, if we assume the angle is acute and measured correctly with a protractor).

Answer:

\( 70 \) (Note: The actual answer may vary depending on the precise measurement with the protractor. If the diagram is such that the angle is, for example, 60 or 80, the answer would change accordingly. But based on typical angle - drawing for such problems, 70 is a common answer.)