Given: Ray E B bisects ∠AEC. ∠AED is a straight angle.

Prove: m∠AEB = 45°

A horizontal line has points A, E, D. 2 lines extend from point E. One line extends to point B and another extends to point C. Angle C E D is a right angle.
Complete the paragraph proof.

We are given that Ray E B bisects ∠AEC. From the diagram, ∠CED is a right angle, which measures blank degrees. Since the measure of a straight angle is 180°, the measure of angle must also be 90° by the blank. A bisector cuts the angle measure in half. m∠AEB is 45°.